SeaMonkey Changelog

What's new in SeaMonkey 2.53.18.2

Mar 28, 2024
  • SeaMonkey 2.53.18.2 contains (among other changes) the following changes relative to SeaMonkey 2.53.18.1:
  • Block set-cookie from multipart/x-mixed-replace with pref bug 1864385.
  • Check if WorkerRunnable::Run runs on top of WorkerThreadPrimaryRunnable::Run in a worker thread bug 1867982.
  • Process pairs in coord list in PolyArea bug 1878211.
  • Cherry-pick update to dav1d bug 1881093.
  • Land NSS NSS_3_90_2_RTM UPGRADE_NSS_RELEASE bug 1880562.
  • Fix DSN for send later bug 815638.
  • Catch webNavigation error during tab restore bug 1885748.
  • SeaMonkey 2.53.18.2 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.18.2 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.18.2 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 115.9 and Thunderbird 115.9 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.

New in SeaMonkey 2.53.18.1 (Jan 19, 2024)

  • The following bugs were fixed in our branch of the Gecko source code only:
  • Update the NSS library to the latest esr 115 version for the final 2.53.18.1 release.
  • SeaMonkey 2.53.18.1 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.18.1 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.18.1 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 115.7 and Thunderbird 115.7 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.

New in SeaMonkey 2.53.18 (Dec 11, 2023)

  • SeaMonkey 2.53.18 contains (among other changes) the following changes relative to SeaMonkey 2.53.17.1:
  • Update Branding info bug 1841167.
  • Use BugSplat for SeaMonkey crash reporting bug 1835524.
  • Unify notifications and permissions in SeaMonkeybug 1849526.
  • The following bugs were fixed in our branch of the Gecko source code only:
  • Update the NSS and NSPR libraries to the esr 115 versions for the final 2.53.18 release.
  • Allow building with system icu again in the final 2.53.18 releasebug 1864745.
  • SeaMonkey 2.53.18 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.18 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.18 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 115.5 and Thunderbird 115.5 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.

New in SeaMonkey 2.53.18 Beta 1 (Nov 15, 2023)

  • What's New in SeaMonkey 2.53.18:
  • SeaMonkey 2.53.18 contains (among other changes) the following changes relative to SeaMonkey 2.53.17.1:
  • Update Branding info bug 1841167.
  • Use BugSplat for SeaMonkey crash reporting bug 1835524.
  • Unify notifications and permissions in SeaMonkeybug 1849526.
  • SeaMonkey 2.53.18 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.18 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.18 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 115.4 and Thunderbird 115.4 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SeaMonkey-specific changes
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.
  • Downloading:
  • The SeaMonkey project provides official versions and language packs of SeaMonkey 2.53.18 Beta 1 for Windows, Linux and macOS in US English and a small variety of other languages. Community volunteers are also contributing builds for other platforms. You can download SeaMonkey 2.53.18 Beta 1 here.
  • System Requirements, Installation and Uninstallation
  • Before installing, make sure your computer meets the system requirements.
  • Please note that the Windows x64 version will only support Windows 7 x64 and up. You need to uninstall a previous Windows x86 version if you want to use it. Installing the x64 over the old x86 is not supported and does not remove the old version which might cause problems later.
  • SeaMonkey 2.53.18 Beta 1 will no longer offer to migrate your data from SeaMonkey 1.x or Mozilla 1.x at the first start after installation (bug 689437). In order to upgrade from such an old version, install the last SeaMonkey 2.0 release first, do the one-time profile upgrade, uninstall SeaMonkey 2.0 and then install your target release (e.g. this one).
  • If you are on an older release we suggest upgrading to SeaMonkey 2.49.5 first.
  • You can find more details about installation, profile data and uninstallation in our install and uninstall document.
  • Extensions (Add-ons) and Themes:
  • Extensions and Themes for SeaMonkey 2.53.18 Beta 1 can be installed from the SeaMonkey Add-Ons website or the "Get Add-Ons" section in the Add-ons Manager.
  • Extensions with binary components such as Enigmail only work for the specific platform they are released (e.g. win extension for Windows, linux64 for Linux 64 bits). Besides, matching version of extensions for SeaMonkey may not be the latest available of those versions. Therefore, they need to be adjusted for each new SeaMonkey release, which also means that an old version of such an add-on can break SeaMonkey if you disabled compatibility checking (which e.g. happens when you install the Add-on Compatibility Reporter add-on). Please, note the following warnings and advice regarding extensions:
  • Previous versions supported a proprietary JavaScript try/catch solution. This was removed in bug 1228841 and needed to be backported to 2.53.10b1. The backport might break some add-ons. One add-on affected is the classic version of DownThemAll. A fixed version is available from the DTA forked repo.
  • For Enigmail, please refer to the Enigmail page.
  • The latest supported version is 3.1.6 Enigmail.
  • Adblock Plus 2.9.1 may cause huge memory and CPU consumption and is not recommended or officially supported in this SeaMonkey version. Consider switching to uBlock.
  • Lightbird 0.7.1. is not compatible with this version. Until a fixed version is released you need to uninstall it.
  • The latest 1.16.x working version of uBlock can be found here. Please install the latest legacy version.
  • The latest 5.1.9 working version of NoScript Classic can be found here.
  • Full theme add-ons are still fully supported but may need changes because of user interface and internal changes. If you find any problem with themes, contact the theme author. Before reporting a problem with the user interface please make sure to recreate it with either the Classic or Modern theme.
  • Lightweight themes are no longer provided on the SeaMonkey Add-ons site and installed existing themes might be broken. Support for web extension themes will be added at a later date.
  • Because of security backports which removed obsolete code, Session Manager add-on version 0.8.1.14 or above is required to be compatible with current and future 2.53 releases.
  • Known Issues:
  • This list covers some of the known problems with SeaMonkey 2.53.18 Beta 1. Please read this before reporting any new bugs.
  • The base user agent version was set to 91 to help with website compatibility. For YouTube do not set the user agent to identify only as Firefox or make sure you are using a site specific user agent for it. YouTube will show only a mostly blank page otherwise in some scenarios. Enhancements for this are planned in bug 1737436.
  • Translations might be missing in a few languages in the user interface and are being substituted with the corresponding US English terms. Some languages like Polish are now missing a translator. Consider helping out with translations if you would like to have a 100% translated version.
  • SeaMonkey might not start under Linux if you downloaded the wrong package.
  • We are providing x86 and x64 versions of SeaMonkey for Linux. For newer distributions you probably need the Linux x64 version.
  • Lightning or one of the distributed extensions is disabled under Add-ons.
  • Starting with SeaMonkey 2.53.7b1 the distributed extensions can no longer be removed. If you have previously enabled one then under some circumstance it might be disabled during the upgrade process. If the extension is disabled and can not be enabled then it is because an old or incompatible version is still present in your profile.
  • To clean out old versions use the following instructions:
  • Enter "about:config" in the location bar.
  • Enter "extensions.installedDistroAddon" in the search field.
  • Reset (delete) all keys found.
  • Open the Add-ons Manager. If the "remove" button is shown for the disabled extension use it. Stored data like your personal calendars will not be removed by this action.
  • Restart SeaMonkey.
  • Disable any distributed extension you do not wish to use.
  • Unable to connect to secure sites and a certificate error is shown.
  • In 99% of all cases this issue is caused by the same problem. Your antivirus software or custom firewall acts as a man in the middle and intercepts secure https traffic. In order to intercept and scan this encrypted network traffic, it normally uses a vendor specific certificate which is not installed by default in SeaMonkey by the third party software installer. If you want to keep this feature working you need to install one or more certificate(s) from the antivirus software in SeaMonkey. You need to ask your antivirus software vendor where they are located. Consult the SeaMonkey online help to find out how you can import and manage certificates.
  • If you experience a hang and/or get a message box warning that a script is busy when opening the Data Manager try deleting the webappsstore.* files from your profile folder when SeaMonkey is not running. These files contain data stored by websites and will be recreated during the next start. If you are unsure if the information is needed please back up the files before deleting them. The problem is tracked in bug 1305624 but so far no coding error has been found. This problem has been reported frequently when trying to manage passwords. But the problem will generally happen just after you open the Data Manager, because this component is also used for managing cookies, site preferences permissions and other settings.
  • If you are running Windows 7 "Send to > Mail recipient" might not work. More information can be found in bug 1356902. As a workaround install the "Microsoft Visual C++ 2015-2019" redistributable runtime library. For x86 install the VS2019 x86 runtime.
  • If you are using the x64 build install the VS2019 x64 runtime. SeaMonkey x64 was built using the latest VS2019 compiler so make sure to upgrade any older VS2017 runtime. Currently the VS2015-VS2022 package is still compatible with Windows 7 too so you could also use this one.
  • If you experience a delay showing the first page after start, please delete the Safebrowsing folder in your profile. Bad Safebrowsing data may delay showing the first page for up to 30 seconds. The problem is tracked in bug 1432274. This can occur even if you are not using Safebrowsing because the lists are always fetched.
  • SeaMonkey does not currently support the WebExtensions add-on api. Some popular add-ons like NoScript and uBlock Origin are no longer shown because of this on the SeaMonkey add-ons website. You can usually get compatible versions from the manufacturers site. WebExtensions support is a planned feature. Dictionaries and language packs in the WebExtensions format are supported.
  • The SSL 3.0 encryption protocol is no longer supported due to security concerns (bug 1106470). Legacy websites may still rely on it and will not work with the newer TLS 1.x protocols. Contact the website administrator to update their server to resolve the issue at the source.
  • The Remember Passwords add-on breaks password handling. Please disable or uninstall this add-on using the Add-ons Manager.
  • You cannot set up a new Sync account or pair a device anymore (bug 998807).
  • Data loss warning: If you use a profile with this or any later version and then try to go back to SeaMonkey 2.49.5 or earlier, SeaMonkey will rename your bookmarks and history file to places.sqlite.corrupt and create a new places.sqlite file, effectively resetting your browsing history. This is because the internal format changed and the upgrade process only works in one direction. Additionally, running MailNews with local folders and POP3 mail filters may produce summary files that are not correctly read by previous versions of SeaMonkey. If you decide to go back to a previous version of SeaMonkey, you should do it from a profile backup only. Stored passwords and local storage will also be unavailable in the old version.
  • After creating a news account through clicking a news URL, the MailNews account wizard may be broken (the account type will always be News). To work around the problem, set the mail.server.serverX.valid pref (where X is the internal number of the corresponding news account) to true in about:config, or delete the invalid news account (bug 521861).
  • WebRTC has been disabled by default. It needs an add-on to enable it per site. See the webrtc-permissions-ui-toggle add-on.
  • Web pages may appear differently in the MailNews feed reader than in the browser (bug 662907). Workaround: Add a "noscript {display:none}" rule to your userContent.css (note that the Stylish add-on cannot be used here since it does not integrate with the MailNews feed reader).
  • Lightning keyboard shortcuts for accessing the calendar tab from within the MailNews window or from the main menu (Ctrl+Shift+C/D) do not work. (bug 514512).
  • If you try to start SeaMonkey using a locked profile, it will crash (see bug 573369).
  • In ChatZilla users are unable to add an exception for an invalid certificate unless an override is added to the preferences (see bug 1720878).
  • Linux:
  • SeaMonkey 2.53.7b1 can not be automatically updated to later beta versions as it is set to the wrong update channel. To overcome this, make sure SeaMonkey 2.53.7b1 is not running, edit the channel-prefs.js file located in the defaults/pref directory of the installation directory for SeaMonkey 2.53.7b1 and change the app.update.channel pref from "release" to "beta". When SeaMonkey is restarted it should then find future beta releases.
  • There is a race condition in libx11 causing applications to randomly abort on Ubuntu based distros (see bug 1743551 and bug 1782984).
  • Windows:
  • You might not be able to install SeaMonkey in Windows 10 if you have turned on the Windows Defender Smartscreen feature. Your SeaMonkey download will be blocked in the case. To overcome this go to "Windows Security->App & browser control" in the new Windows Settings and set the "Check apps and files" setting to Warn from Block.
  • Antivirus scanners may report that some parts of SeaMonkey (e.g. the file freebl3.dll) are suspicious. If you downloaded SeaMonkey from one of the official download sites, this is a false alarm. You might experience problems with secure websites when this happens. To fix the issue, instruct your antivirus software to ignore these files (and move them out of quarantine) and/or switch to another antivirus software and reinstall SeaMonkey.
  • macOS:
  • The scrollbar is not always visible on some websites under recent macOS versions (10.15 upwards) see bug 1684651.
  • You might not be able to install SeaMonkey under recent macOS versions. In this case please read Open a Mac app from an unidentified developer for a solution.
  • When hardware acceleration is off, background colors in the UI (toolbar, status bar etc.) might not update correctly when you switch focus from/to a window. Users running Macs with certain older hardware will experience this even if they haven't turned off hardware acceleration in Preferences (Appearance/Content) (bug 626096).
  • SeaMonkey 2.53.7b1 can not be automatically updated to later beta versions as it is set to the wrong update channel. To overcome this, make sure SeaMonkey 2.53.7b1 is not running, edit the channel-prefs.js file located in the Contents/Resources/defaults/pref folder of the installation folder for SeaMonkey 2.53.7b1 and change the app.update.channel pref from "release" to "beta". When SeaMonkey is restarted it should then find future beta releases.

New in SeaMonkey 2.53.17.1 (Sep 23, 2023)

  • SeaMonkey 2.53.17.1 contains (among other changes) the following changes relative to SeaMonkey 2.53.17:
  • Upstream libwebp security fix bug 1852749.
  • CVE-2023-4863: Heap buffer overflow in libwebp bug 1852649.
  • Fix bad string encoded in ansi. l10n fr problem only bug 1847887.
  • SeaMonkey 2.53.17.1 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.17.1 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.17.1 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 115.3 and Thunderbird 115.3 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SeaMonkey-specific changes:
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.
  • Downloading:
  • The SeaMonkey project provides official versions and language packs of SeaMonkey 2.53.17.1 for Windows, Linux and macOS in US English and a small variety of other languages. Community volunteers are also contributing builds for other platforms. You can download SeaMonkey 2.53.17.1 here.
  • System Requirements, Installation and Uninstallation
  • Before installing, make sure your computer meets the system requirements.
  • Please note that the Windows x64 version will only support Windows 7 x64 and up. You need to uninstall a previous Windows x86 version if you want to use it. Installing the x64 over the old x86 is not supported and does not remove the old version which might cause problems later.
  • SeaMonkey 2.53.17.1 will no longer offer to migrate your data from SeaMonkey 1.x or Mozilla 1.x at the first start after installation (bug 689437). In order to upgrade from such an old version, install the last SeaMonkey 2.0 release first, do the one-time profile upgrade, uninstall SeaMonkey 2.0 and then install your target release (e.g. this one).
  • If you are on an older release we suggest upgrading to SeaMonkey 2.49.5 first.
  • You can find more details about installation, profile data and uninstallation in our install and uninstall document.
  • Extensions (Add-ons) and Themes:
  • Extensions and Themes for SeaMonkey 2.53.17.1 can be installed from the SeaMonkey Add-Ons website or the "Get Add-Ons" section in the Add-ons Manager.
  • Extensions with binary components such as Enigmail only work for the specific platform they are released (e.g. win extension for Windows, linux64 for Linux 64 bits). Besides, matching version of extensions for SeaMonkey may not be the latest available of those versions. Therefore, they need to be adjusted for each new SeaMonkey release, which also means that an old version of such an add-on can break SeaMonkey if you disabled compatibility checking (which e.g. happens when you install the Add-on Compatibility Reporter add-on). Please, note the following warnings and advice regarding extensions:
  • Previous versions supported a proprietary JavaScript try/catch solution. This was removed in bug 1228841 and needed to be backported to 2.53.10b1. The backport might break some add-ons. One add-on affected is the classic version of DownThemAll. A fixed version is available from the DTA forked repo.
  • For Enigmail, please refer to the Enigmail page.
  • The latest supported version is 3.1.4 Enigmail.
  • Adblock Plus 2.9.1 may cause huge memory and CPU consumption and is not recommended or officially supported in this SeaMonkey version. Consider switching to uBlock.
  • Lightbird 0.7.1. is not compatible with this version. Until a fixed version is released you need to uninstall it.
  • The latest 1.16.x working version of uBlock can be found here. Please install the latest legacy version.
  • The latest working version of NoScript Classic 5.x can be found here.
  • Full theme add-ons are still fully supported but may need changes because of user interface and internal changes. If you find any problem with themes, contact the theme author. Before reporting a problem with the user interface please make sure to recreate it with either the Classic or Modern theme.
  • Lightweight themes are no longer provided on the SeaMonkey Add-ons site and installed existing themes might be broken. Support for web extension themes will be added at a later date.
  • Because of security backports which removed obsolete code, Session Manager add-on version 0.8.1.14 or above is required to be compatible with current and future 2.53 releases.
  • Known Issues:
  • This list covers some of the known problems with SeaMonkey 2.53.17.1. Please read this before reporting any new bugs.
  • The base user agent version was set to 91 to help with website compatibility. For YouTube do not set the user agent to identify only as Firefox or make sure you are using a site specific user agent for it. YouTube will show only a mostly blank page otherwise in some scenarios. Enhancements for this are planned in bug 1737436.
  • Translations might be missing in a few languages in the user interface and are being substituted with the corresponding US English terms. Some languages like Polish are now missing a translator. Consider helping out with translations if you would like to have a 100% translated version.
  • SeaMonkey will not start under Linux if you downloaded the wrong package.
  • We are providing x86 and x64 versions of SeaMonkey for Linux. For newer distributions you probably need the Linux x64 version.
  • Lightning or one of the distributed extensions is disabled under Add-ons.
  • Starting with SeaMonkey 2.53.7b1 the distributed extensions can no longer be removed. If you have previously enabled one then under some circumstance it might be disabled during the upgrade process. If the extension is disabled and can not be enabled then it is because an old or incompatible version is still present in your profile.
  • To clean out old versions use the following instructions:
  • Enter "about:config" in the location bar.
  • Enter "extensions.installedDistroAddon" in the search field.
  • Reset (delete) all keys found.
  • Open the Add-ons Manager. If the "remove" button is shown for the disabled extension use it. Stored data like your personal calendars will not be removed by this action.
  • Restart SeaMonkey.
  • Disable any distributed extension you do not wish to use.
  • Unable to connect to secure sites and a certificate error is shown.
  • In 99% of all cases this issue is caused by the same problem. Your antivirus software or custom firewall acts as a man in the middle and intercepts secure https traffic. In order to intercept and scan this encrypted network traffic, it normally uses a vendor specific certificate which is not installed by default in SeaMonkey by the third party software installer. If you want to keep this feature working you need to install one or more certificate(s) from the antivirus software in SeaMonkey. You need to ask your antivirus software vendor where they are located. Consult the SeaMonkey online help to find out how you can import and manage certificates.
  • If you experience a hang and/or get a message box warning that a script is busy when opening the Data Manager try deleting the webappsstore.* files from your profile folder when SeaMonkey is not running. These files contain data stored by websites and will be recreated during the next start. If you are unsure if the information is needed please back up the files before deleting them. The problem is tracked in bug 1305624 but so far no coding error has been found. This problem has been reported frequently when trying to manage passwords. But the problem will generally happen just after you open the Data Manager, because this component is also used for managing cookies, site preferences permissions and other settings.
  • If you are running Windows 7 "Send to > Mail recipient" might not work. More information can be found in bug 1356902. As a workaround install the "Microsoft Visual Studio 2015 to 2019" redistributable runtime library. For x86 install the VS2019 x86 runtime.
  • If you are using the x64 build install the VS2019 x64 runtime. SeaMonkey was built using the latest VS2019 compiler so make sure to upgrade any older VS2017 runtime.
  • If you experience a delay showing the first page after start, please delete the Safebrowsing folder in your profile. Bad Safebrowsing data may delay showing the first page for up to 30 seconds. The problem is tracked in bug 1432274. This can occur even if you are not using Safebrowsing because the lists are always fetched.
  • SeaMonkey does not currently support the WebExtensions add-on api. Some popular add-ons like NoScript and uBlock Origin are no longer shown because of this on the SeaMonkey add-ons website. You can usually get compatible versions from the manufacturers site. WebExtensions support is a planned feature. Dictionaries and language packs in the WebExtensions format are supported.
  • The SSL 3.0 encryption protocol is no longer supported due to security concerns (bug 1106470). Legacy websites may still rely on it and will not work with the newer TLS 1.x protocols. Contact the website administrator to update their server to resolve the issue at the source.
  • The Remember Passwords add-on breaks password handling. Please disable or uninstall this add-on using the Add-ons Manager.
  • You cannot set up a new Sync account or pair a device anymore (bug 998807).
  • Data loss warning: If you use a profile with this or any later version and then try to go back to SeaMonkey 2.49.5 or earlier, SeaMonkey will rename your bookmarks and history file to places.sqlite.corrupt and create a new places.sqlite file, effectively resetting your browsing history. This is because the internal format changed and the upgrade process only works in one direction. Additionally, running MailNews with local folders and POP3 mail filters may produce summary files that are not correctly read by previous versions of SeaMonkey. If you decide to go back to a previous version of SeaMonkey, you should do it from a profile backup only. Stored passwords and local storage will also be unavailable in the old version.
  • After creating a news account through clicking a news URL, the MailNews account wizard may be broken (the account type will always be News). To work around the problem, set the mail.server.serverX.valid pref (where X is the internal number of the corresponding news account) to true in about:config, or delete the invalid news account (bug 521861).
  • WebRTC has been disabled by default. It needs an add-on to enable it per site. See the webrtc-permissions-ui-toggle add-on.
  • Web pages may appear differently in the MailNews feed reader than in the browser (bug 662907). Workaround: Add a "noscript {display:none}" rule to your userContent.css (note that the Stylish add-on cannot be used here since it does not integrate with the MailNews feed reader).
  • Lightning keyboard shortcuts for accessing the calendar tab from within the MailNews window or from the main menu (Ctrl+Shift+C/D) do not work. (bug 514512).
  • If you try to start SeaMonkey using a locked profile, it will crash (see bug 573369).
  • In ChatZilla users are unable to add an exception for an invalid certificate unless an override is added to the preferences (see bug 1720878).
  • Linux:
  • SeaMonkey 2.53.7b1 can not be automatically updated to later beta versions as it is set to the wrong update channel. To overcome this, make sure SeaMonkey 2.53.7b1 is not running, edit the channel-prefs.js file located in the defaults/pref directory of the installation directory for SeaMonkey 2.53.7b1 and change the app.update.channel pref from "release" to "beta". When SeaMonkey is restarted it should then find future beta releases.
  • There is a race condition in libx11 causing applications to randomly abort on Ubuntu based distros (see bug 1743551 and bug 1782984).
  • Windows:
  • You might not be able to install SeaMonkey in Windows 10 if you have turned on the Windows Defender Smartscreen feature. Your SeaMonkey download will be blocked in the case. To overcome this go to "Windows Security->App & browser control" in the new Windows Settings and set the "Check apps and files" setting to Warn from Block.
  • Antivirus scanners may report that some parts of SeaMonkey (e.g. the file freebl3.dll) are suspicious. If you downloaded SeaMonkey from one of the official download sites, this is a false alarm. You might experience problems with secure websites when this happens. To fix the issue, instruct your antivirus software to ignore these files (and move them out of quarantine) and/or switch to another antivirus software and reinstall SeaMonkey.
  • macOS:
  • The scrollbar is not always visible on some websites under recent macOS versions (10.15 upwards) see bug 1684651.
  • You might not be able to install SeaMonkey under recent macOS versions. In this case please read Open a Mac app from an unidentified developer for a solution.
  • When hardware acceleration is off, background colors in the UI (toolbar, status bar etc.) might not update correctly when you switch focus from/to a window. Users running Macs with certain older hardware will experience this even if they haven't turned off hardware acceleration in Preferences (Appearance/Content) (bug 626096).
  • SeaMonkey 2.53.7b1 can not be automatically updated to later beta versions as it is set to the wrong update channel. To overcome this, make sure SeaMonkey 2.53.7b1 is not running, edit the channel-prefs.js file located in the Contents/Resources/defaults/pref folder of the installation folder for SeaMonkey 2.53.7b1 and change the app.update.channel pref from "release" to "beta". When SeaMonkey is restarted it should then find future beta releases.
  • Troubleshooting:
  • Some questions are asked more frequently than others. Have a look at the SeaMonkey FAQ. Maybe your particular problem has already been solved.
  • Some antivirus software keeps detecting our installers as containing a "Trojan" or "Downloader". This is a false positive because of some wrong detection mechanism in the antivirus software. The code in question is actually from 7-Zip and decompresses the installer so that its contents can run and install SeaMonkey. That technology is widely used and probably can be used to compress bad as well as good software, but the 7-Zip code itself is perfectly safe. Mozilla scans all our files routinely when putting them on the FTP server and we assure you that our installers are as clean as the official Firefox downloads that are scanned by the same mechanisms.
  • For security, parts of bug 1035091 were ported in bug 1411708. This might cause problems with add-ons like Stylish which use moz-document. Set the preference "layout.css.moz-document.content.enabled" to "true" to overcome this but be aware that this disables the added security fix.
  • Poorly designed or incompatible extensions can cause problems with SeaMonkey, including make it crash, slow down page display, etc. If you encounter strange problems relating to parts of SeaMonkey no longer working, the browser not starting, windows with strange or distorted appearance, degraded performance, etc, you may be suffering from Extension or Theme trouble. Restart SeaMonkey in Safe Mode. On Windows, start using the "Safe Mode" shortcut created in your Start menu or by running seamonkey.exe -safe-mode. On Linux, start with /path-to-seamonkey/seamonkey -safe-mode or first change to the SeaMonkey installation directory and start with ./seamonkey -safe-mode, and on macOS, run:
  • cd /Applications/SeaMonkey.app/Contents/MacOS/
  • ./seamonkey-bin -safe-mode
  • When started in Safe Mode all extensions are disabled and the Default theme is used. Disable the Extension/Theme that is causing trouble and then start normally.
  • If you uninstall an extension that is installed with your user profile (i.e. you installed it from a Web page) and then wish to install it for all user profiles using the -install-global-extension command line flag, you must restart SeaMonkey once to cleanse the profile extensions datasource of traces of that extension before installing with the switch. If you do not do this you may end up with a jammed entry in the Extensions list and will be unable to install the extension globally.
  • If you encounter strange problems relating to bookmarks, downloads, window placement, toolbars, history, or other settings, it is recommended that you try creating a new profile and attempting to reproduce the problem before filing bugs. Create a new profile by running SeaMonkey with the -P command line argument, choose the "Manage Profiles" button and then choose "Create Profile...". Migrate your settings files (Bookmarks, Saved Passwords, etc) over one by one, checking each time to see if the problems resurface. If you do find a particular profile data file is causing a problem, file a bug and attach the file.

New in SeaMonkey 2.53.17 (Aug 7, 2023)

  • SeaMonkey 2.53.17 contains (among other changes) the following major changes relative to SeaMonkey 2.53.16:
  • Fix macOS Contacts permission request bug 1826719.
  • Remove SeaMonkey 2.57 links from debugQA bug 1829683.
  • Treat opening urls from the library as external bug 1619108.
  • Disable spam warning for autogenerated links in plaintext messages bug 619031.
  • Switch SeaMonkey build files to Python 3 bug 1635849.
  • Remove empty overlays from Composer bug 1828533.
  • Move xpfe autocomplete to comm-central suite bug 1418512.
  • Remove nsIPrefBranch2 and nsIPrefBranchInternal bug 1374847.
  • SeaMonkey 2.53.17 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.17 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.17 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 102.11 and Thunderbird 102.11 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SeaMonkey-specific changes:
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.

New in SeaMonkey 2.53.17 Beta 1 (Jun 20, 2023)

  • What's New in SeaMonkey 2.53.17:
  • SeaMonkey 2.53.17 contains (among other changes) the following major changes relative to SeaMonkey 2.53.16:
  • Fix macOS Contacts permission request bug 1826719.
  • Remove SeaMonkey 2.57 links from debugQA bug 1829683.
  • Treat opening urls from the library as external bug 1619108.
  • Disable spam warning for autogenerated links in plaintext messages bug 619031.
  • Switch SeaMonkey build files to Python 3 bug 1635849.
  • Remove empty overlays from Composer bug 1828533.
  • Move xpfe autocomplete to comm-central suite bug 1418512.
  • Remove nsIPrefBranch2 and nsIPrefBranchInternal bug 1374847.
  • Continue the switch from Python 2 to Python 3 in the build system.
  • SeaMonkey 2.53.17 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.17 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.17 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 102.11 and Thunderbird 102.11 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SeaMonkey-specific changes:
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug and link it to bug 1367257. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.
  • Downloading:
  • The SeaMonkey project provides official versions and language packs of SeaMonkey 2.53.17 Beta 1 for Windows, Linux and macOS in US English and a small variety of other languages. Community volunteers are also contributing builds for other platforms. You can download SeaMonkey 2.53.17 Beta 1 here.
  • System Requirements, Installation and Uninstallation
  • Before installing, make sure your computer meets the system requirements.
  • Please note that the new Windows x64 version will only support Windows 7 x64 and up. You need to uninstall a previous Windows x86 version if you want to use it. Installing the x64 over the old x86 is not supported and does not remove the old version which might cause problems later.
  • SeaMonkey 2.53.17 Beta 1 will no longer offer to migrate your data from SeaMonkey 1.x or Mozilla 1.x at the first start after installation (bug 689437). In order to upgrade from such an old version, install the last SeaMonkey 2.0 release first, do the one-time profile upgrade, uninstall SeaMonkey 2.0 and then install your target release (e.g. this one).
  • If you are on an older release we suggest upgrading to SeaMonkey 2.49.5 first.
  • You can find more details about installation, profile data and uninstallation in our install and uninstall document.
  • Extensions (Add-ons) and Themes:
  • Extensions and Themes for SeaMonkey 2.53.17 Beta 1 can be installed from the SeaMonkey Add-Ons website or the "Get Add-Ons" section in the Add-ons Manager.
  • Extensions with binary components such as Enigmail only work for the specific platform they are released (e.g. win extension for Windows, linux64 for Linux 64 bits). Besides, matching version of extensions for SeaMonkey may not be the latest available of those versions. Therefore, they need to be adjusted for each new SeaMonkey release, which also means that an old version of such an add-on can break SeaMonkey if you disabled compatibility checking (which e.g. happens when you install the Add-on Compatibility Reporter add-on). Please, note the following warnings and advice regarding extensions:
  • Previous versions supported a proprietary JavaScript try/catch solution. This was removed in bug 1228841 and needed to be backported to 2.53.10b1. The backport might break some add-ons. One add-on affected is the classic version of DownThemAll. A fixed version is available from the DTA forked repo.
  • For Enigmail, please refer to the Enigmail page.
  • The latest supported version is 2.0.9 Enigmail but there have been some problems reported against it.
  • Adblock Plus 2.9.1 may cause huge memory and CPU consumption and is not recommended or officially supported in this SeaMonkey version. Consider switching to uBlock.
  • Lightbird 0.7.1. is not compatible with this version. The message preview pane will not update itself correctly.
  • The latest 1.16.x working version of uBlock can be found here. Please install the latest legacy version.
  • The latest working version of NoScript Classic 5.x can be found here.
  • Lightweight themes are no longer provided on the SeaMonkey Add-ons site.
  • Full theme add-ons may need changes because of user interface and internal changes. If you find any problem with themes, contact the theme author. Before reporting a problem with the user interface please make sure to recreate it with either the Classic or Modern theme.
  • Because of security backports which removed obsolete code, Session Manager add-on version 0.8.1.14 or above is required to be compatible with current and future 2.53 releases.
  • Known Issues:
  • This list covers some of the known problems with SeaMonkey 2.53.17 Beta 1. Please read this before reporting any new bugs.
  • The base user agent version was set to 91 to help with website compatibility. For YouTube do not set the user agent to identify only as Firefox or make sure you are using a site specific user agent for it. YouTube will show only a mostly blank page otherwise in some scenarios. Enhancements for this are planned in bug 1737436.
  • Translations might be missing in a few languages in the user interface and are being substituted with the corresponding US English terms. Some languages like Polish are now missing a translator. Consider helping out with translations if you would like to have a 100% translated version.
  • Opening single new tabs from the Library always loads them in the foreground. The problem is tracked in bug 1619108
  • SeaMonkey will not start under Linux if you downloaded the wrong package.
  • We are providing x86 and x64 versions of SeaMonkey for Linux. For newer distributions you probably need the Linux x64 version.
  • Lightning or one of the distributed extensions is disabled under Add-ons.
  • Starting with SeaMonkey 2.53.7b1 the distributed extensions can no longer be removed. If you have previously enabled one then under some circumstance it might be disabled during the upgrade process. If the extension is disabled and can not be enabled then it is because an old or incompatible version is still present in your profile.
  • To clean out old versions use the following instructions:
  • Enter "about:config" in the location bar.
  • Enter "extensions.installedDistroAddon" in the search field.
  • Reset (delete) all keys found.
  • Open the Add-ons Manager. If the "remove" button is shown for the disabled extension use it. Stored data like your personal calendars will not be removed by this action.
  • Restart SeaMonkey.
  • Disable any distributed extension you do not wish to use.
  • Unable to connect to secure sites and a certificate error is shown.
  • In 99% of all cases this issue is caused by the same problem. Your antivirus software or custom firewall acts as a man in the middle and intercepts secure https traffic. In order to intercept and scan this encrypted network traffic, it normally uses a vendor specific certificate which is not installed by default in SeaMonkey by the third party software installer. If you want to keep this feature working you need to install one or more certificate(s) from the antivirus software in SeaMonkey. You need to ask your antivirus software vendor where they are located. Consult the SeaMonkey online help to find out how you can import and manage certificates.
  • If you experience a hang and/or get a message box warning that a script is busy when opening the Data Manager try deleting the webappsstore.* files from your profile folder when SeaMonkey is not running. These files contain data stored by websites and will be recreated during the next start. If you are unsure if the information is needed please back up the files before deleting them. The problem is tracked in bug 1305624 but so far no coding error has been found. This problem has been reported frequently when trying to manage passwords. But the problem will generally happen just after you open the Data Manager, because this component is also used for managing cookies, site preferences permissions and other settings.
  • If you are running Windows 7 "Send to > Mail recipient" might not work. More information can be found in bug 1356902. As a workaround install the "Microsoft Visual Studio 2015 to 2019" redistributable runtime library. For x86 install the VS2019 x86 runtime.
  • If you are using the x64 build install the VS2019 x64 runtime. SeaMonkey was built using the latest VS2019 compiler so make sure to upgrade any older VS2017 runtime.
  • If you experience a delay showing the first page after start, please delete the Safebrowsing folder in your profile. Bad Safebrowsing data may delay showing the first page for up to 30 seconds. The problem is tracked in bug 1432274. This can occur even if you are not using Safebrowsing because the lists are always fetched.
  • SeaMonkey does not currently support the WebExtensions add-on api. Some popular add-ons like NoScript and uBlock Origin are no longer shown because of this on the SeaMonkey add-ons website. You can usually get compatible versions from the manufacturers site. WebExtensions support is a planned feature. Dictionaries and language packs in the WebExtensions format are supported.
  • The SSL 3.0 encryption protocol is no longer supported due to security concerns (bug 1106470). Legacy websites may still rely on it and will not work with the newer TLS 1.x protocols. Contact the website administrator to update their server to resolve the issue at the source.
  • The Remember Passwords add-on breaks password handling. Please disable or uninstall this add-on using the Add-ons Manager.
  • You cannot set up a new Sync account or pair a device anymore (bug 998807).
  • Data loss warning: If you use a profile with this or any later version and then try to go back to SeaMonkey 2.49.5 or earlier, SeaMonkey will rename your bookmarks and history file to places.sqlite.corrupt and create a new places.sqlite file, effectively resetting your browsing history. This is because the internal format changed and the upgrade process only works in one direction. Additionally, running MailNews with local folders and POP3 mail filters may produce summary files that are not correctly read by previous versions of SeaMonkey. If you decide to go back to a previous version of SeaMonkey, you should do it from a profile backup only. Stored passwords and local storage will also be unavailable in the old version.
  • After creating a news account through clicking a news URL, the MailNews account wizard may be broken (the account type will always be News). To work around the problem, set the mail.server.serverX.valid pref (where X is the internal number of the corresponding news account) to true in about:config, or delete the invalid news account (bug 521861).
  • WebRTC has been disabled by default. It needs an add-on to enable it per site. See the webrtc-permissions-ui-toggle add-on.
  • Web pages may appear differently in the MailNews feed reader than in the browser (bug 662907). Workaround: Add a "noscript {display:none}" rule to your userContent.css (note that the Stylish add-on cannot be used here since it does not integrate with the MailNews feed reader).
  • Lightning keyboard shortcuts for accessing the calendar tab from within the MailNews window or from the main menu (Ctrl+Shift+C/D) do not work. (bug 514512).
  • If you try to start SeaMonkey using a locked profile, it will crash (see bug 573369).
  • In ChatZilla users are unable to add an exception for an invalid certificate unless an override is added to the preferences (see bug 1738597).
  • Linux:
  • SeaMonkey 2.53.7b1 can not be automatically updated to later beta versions as it is set to the wrong update channel. To overcome this, make sure SeaMonkey 2.53.7b1 is not running, edit the channel-prefs.js file located in the defaults/pref directory of the installation directory for SeaMonkey 2.53.7b1 and change the app.update.channel pref from "release" to "beta". When SeaMonkey is restarted it should then find future beta releases.
  • There is a race condition in libx11 causing applications to randomly abort on Ubuntu based distros (see bug 1743551 and bug 1782984).
  • Windows:
  • You might not be able to install SeaMonkey in Windows 10 if you have turned on the Windows Defender Smartscreen feature. Your SeaMonkey download will be blocked in the case. To overcome this go to "Windows Security->App & browser control" in the new Windows Settings and set the "Check apps and files" setting to Warn from Block.
  • Antivirus scanners may report that some parts of SeaMonkey (e.g. the file freebl3.dll) are suspicious. If you downloaded SeaMonkey from one of the official download sites, this is a false alarm. You might experience problems with secure websites when this happens. To fix the issue, instruct your antivirus software to ignore these files (and move them out of quarantine) and/or switch to another antivirus software and reinstall SeaMonkey.
  • macOS:
  • The scrollbar is not always visible on some websites under recent macOS versions (10.15 upwards) see bug 1684651.
  • You might not be able to install SeaMonkey under recent macOS versions. In this case please read Open a Mac app from an unidentified developer for a solution.
  • When hardware acceleration is off, background colors in the UI (toolbar, status bar etc.) might not update correctly when you switch focus from/to a window. Users running Macs with certain older hardware will experience this even if they haven't turned off hardware acceleration in Preferences (Appearance/Content) (bug 626096).
  • SeaMonkey 2.53.7b1 can not be automatically updated to later beta versions as it is set to the wrong update channel. To overcome this, make sure SeaMonkey 2.53.7b1 is not running, edit the channel-prefs.js file located in the Contents/Resources/defaults/pref folder of the installation folder for SeaMonkey 2.53.7b1 and change the app.update.channel pref from "release" to "beta". When SeaMonkey is restarted it should then find future beta releases.
  • Troubleshooting:
  • Some questions are asked more frequently than others. Have a look at the SeaMonkey FAQ. Maybe your particular problem has already been solved.
  • Some antivirus software keeps detecting our installers as containing a "Trojan" or "Downloader". This is a false positive because of some wrong detection mechanism in the antivirus software. The code in question is actually from 7-Zip and decompresses the installer so that its contents can run and install SeaMonkey. That technology is widely used and probably can be used to compress bad as well as good software, but the 7-Zip code itself is perfectly safe. Mozilla scans all our files routinely when putting them on the FTP server and we assure you that our installers are as clean as the official Firefox downloads that are scanned by the same mechanisms.
  • For security, parts of bug 1035091 were ported in bug 1411708. This might cause problems with add-ons like Stylish which use moz-document. Set the preference "layout.css.moz-document.content.enabled" to "true" to overcome this but be aware that this disables the added security fix.
  • Poorly designed or incompatible extensions can cause problems with SeaMonkey, including make it crash, slow down page display, etc. If you encounter strange problems relating to parts of SeaMonkey no longer working, the browser not starting, windows with strange or distorted appearance, degraded performance, etc, you may be suffering from Extension or Theme trouble. Restart SeaMonkey in Safe Mode. On Windows, start using the "Safe Mode" shortcut created in your Start menu or by running seamonkey.exe -safe-mode. On Linux, start with /path-to-seamonkey/seamonkey -safe-mode or first change to the SeaMonkey installation directory and start with ./seamonkey -safe-mode, and on macOS, run:
  • cd /Applications/SeaMonkey.app/Contents/MacOS/
  • ./seamonkey-bin -safe-mode
  • When started in Safe Mode all extensions are disabled and the Default theme is used. Disable the Extension/Theme that is causing trouble and then start normally.
  • If you uninstall an extension that is installed with your user profile (i.e. you installed it from a Web page) and then wish to install it for all user profiles using the -install-global-extension command line flag, you must restart SeaMonkey once to cleanse the profile extensions datasource of traces of that extension before installing with the switch. If you do not do this you may end up with a jammed entry in the Extensions list and will be unable to install the extension globally.
  • If you encounter strange problems relating to bookmarks, downloads, window placement, toolbars, history, or other settings, it is recommended that you try creating a new profile and attempting to reproduce the problem before filing bugs. Create a new profile by running SeaMonkey with the -P command line argument, choose the "Manage Profiles" button and then choose "Create Profile...". Migrate your settings files (Bookmarks, Saved Passwords, etc) over one by one, checking each time to see if the problems resurface. If you do find a particular profile data file is causing a problem, file a bug and attach the file.

New in SeaMonkey 2.53.16 (Apr 2, 2023)

  • The SeaMonkey project is proud to present SeaMonkey 2.53.16: The new release of the all-in-one Internet suite is available for download now! 2.53.16 is an incremental update from the 2.53.x branch and incorporates a number of changes as well as fixes from the underlying platform code.
  • There is now support for webextension dictionaries and language packs and there is a new shared styling for trees. Some minor updates to web compatibility. Minimum supported macOS version is now 10.11.
  • SeaMonkey 2.53.16 is available in 23 languages, for Windows, macOS x64 and Linux.
  • Automatic upgrades from previous 2.53.x versions are enabled for this release, but if you have problems with it upgrading or you need to upgrade from a version earlier than 2.53.5, please download the full installer from the downloads section and install SeaMonkey 2.53.16 manually over the previous version.
  • eaMonkey 2.53.16 contains (among other changes) the following major changes relative to SeaMonkey 2.53.15:
  • No throbber in plaintext editor bug 85498.
  • Remove unused gridlines class from EdAdvancedEdit bug 1806632.
  • Remove ESR 91 links from debugQA bug 1804534.
  • Rename devtools/shim to devtools/startup bug 1812367.
  • Remove unused seltype=text|cell css bug 1806653.
  • Implement new shared tree styling bug 1807802.
  • Use `win.focus()` in macWindowMenu.js bug 1807817.
  • Remove WCAP provider bug 1579020.
  • Remove ftp/file tree view support bug 1239239.
  • Change calendar list tree to a list bug 1561530.
  • Various other updates to the calendar code.
  • Continue the switch from Python 2 to Python 3 in the build system.
  • Verified compatibility with Rust 1.66.1.
  • SeaMonkey 2.53.16 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.16 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.16 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 102.9 and Thunderbird 102.9 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SeaMonkey-specific changes:
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug and link it to bug 1367257. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.
  • Extensions (Add-ons) and Themes:
  • Extensions and Themes for SeaMonkey 2.53.16 can be installed from the SeaMonkey Add-Ons website or the "Get Add-Ons" section in the Add-ons Manager.
  • Extensions with binary components such as Enigmail only work for the specific platform they are released (e.g. win extension for Windows, linux64 for Linux 64 bits). Besides, matching version of extensions for SeaMonkey may not be the latest available of those versions. Therefore, they need to be adjusted for each new SeaMonkey release, which also means that an old version of such an add-on can break SeaMonkey if you disabled compatibility checking (which e.g. happens when you install the Add-on Compatibility Reporter add-on). Please, note the following warnings and advice regarding extensions:
  • Previous versions supported a proprietary JavaScript try/catch solution. This was removed in bug 1228841 and needed to be backported to 2.53.10b1. The backport might break some add-ons. One add-on affected is the classic version of DownThemAll. A fixed version is available from the DTA forked repo.
  • For Enigmail, please refer to the Enigmail page.
  • The latest supported version is 2.0.9 Enigmail but there have been some problems reported against it.
  • Adblock Plus 2.9.1 may cause huge memory and CPU consumption and is not recommended or officially supported in this SeaMonkey version. Consider switching to uBlock.
  • Lightbird 0.7.1. is not compatible with this version. The message preview pane will not update itself correctly.
  • The latest 1.16.x working version of uBlock can be found here. Please install the latest legacy version.
  • The latest working version of NoScript Classic 5.x can be found here.
  • Dictionaries in WebExtension formats do not work, even though they appear to install correctly. Support for them will be added at a later date. Please install the latest classic version from the dictionary history or unpack the dictionary inside the WebExtension package into your /dictionaries directory.
  • Lightweight themes are no longer provided on the SeaMonkey Add-ons site.
  • Full theme add-ons may need changes because of user interface and internal changes. If you find any problem with themes, contact the theme author. Before reporting a problem with the user interface please make sure to recreate it with either the Classic or Modern theme.
  • Because of security backports which removed obsolete code, Session Manager add-on version 0.8.1.14 or above is required to be compatible with current and future 2.53 releases.

New in SeaMonkey 2.53.16 Beta 1 (Mar 1, 2023)

  • SeaMonkey 2.53.16 contains (among other changes) the following major changes relative to SeaMonkey 2.53.15:
  • No throbber in plaintext editor bug 85498.
  • Remove unused gridlines class from EdAdvancedEdit bug 1806632.
  • Remove ESR 91 links from debugQA bug 1804534.
  • Rename devtools/shim to devtools/startup bug 1812367.
  • Remove unused seltype=text|cell css bug 1806653.
  • Implement new shared tree styling bug 1807802.
  • Use `win.focus()` in macWindowMenu.js bug 1807817.
  • Remove WCAP provider bug 1579020.
  • Remove ftp/file tree view support bug 1239239.
  • Change calendar list tree to a list bug 1561530.
  • Various other updates to the calendar code.
  • Continue the switch from Python 2 to Python 3 in the build system.
  • Verified compatibility with Rust 1.66.1.

New in SeaMonkey 2.53.15 (Jan 20, 2023)

  • SeaMonkey 2.53.15 contains (among other changes) the following major changes relative to SeaMonkey 2.53.14:
  • Microtasks and promises bug 1193394.
  • Implement queueMicrotask()bug 1480236.
  • Remove old synchronous contentPrefService from the tree bug 886907 and bug 1392929.
  • Remove remaining uses of 'general.useragent.locale' bug 1410736 and bug 1410738.
  • Migrate to intl.locale.requested.locale list from 'general.useragent.locale' bug 1441016.
  • Introduce a pref to store BCP47 locale list bug 1414390, bug 1423532 and bug 1441026.
  • Remove synchronous certificate verification APIs from nsIX509CertDB bug 1453741 and bug 1453778.
  • Taskbar preview's favicon appears blank bug 1475524.
  • Call Imagelibs decodeImageAsyncWindows using a callback bug 1790695.
  • Remove PermissionsService from process Windows sandboxing code bug 1788233, bug 1789782 and bug 1794394.
  • Security info dialog doesn't show cert status anymore bug 1293378.
  • Replace nsIPlatfromCharset in mailnews bug 1381762.
  • Replace use of nsMsgI18NFileSystemCharset() with NS_CopyUnicodeToNative/NS_CopyNativeToUnicode() bug 1506422.
  • Cater for Outlook's/Hotmail's 'Deleted' folder bug 1320191.
  • Make some filter methods scriptable bug 1497513.
  • Fix crash in nsMsgFilterAfterTheFact::ApplyFilter() caused by async reset of 'm_curFolder' bug 537017.
  • Localize messages from nsIMsgFolder.logRuleHitFail() bug 1352731.
  • Add logging of message filter runs and actions bug 697522.
  • Check that we got a non-null header before running a filter on it (and crashing) bug 1563959.
  • With CONDSTORE, eliminate unneeded flag fetches at startup bug 1428097.
  • Fix so custom tags (keywords) are visible to all users bug 583677.
  • Improve handling of tags on shared folders bug 1596371.
  • Allow setting/resetting junk marking by user for yahoo/aol to stick bug 1260059.
  • Don't check subject if spellchecker is not ready bug 1069787.
  • Grammar issues in mailnews_account_settings.xhtml bug 1793291.
  • Remove use of nsIMemory bug 1792578.
  • Replace obsolete GetStringBundleService call in SeaMonkey bug 1794400.
  • SeaMonkey crashes on macOS Ventura 13.0 bug 1797696.
  • Website Navigation Bar has stopped working bug 1803918.
  • SeaMonkey switch to fullscreen does not work on macOS Ventura 13.0 bug 1804537.
  • Continue the switch from Python 2 to Python 3 in the build system.
  • Added support for clang 15 and macOS SDK 11.3.
  • Verified compatibility with Rust 1.65.
  • SeaMonkey 2.53.15 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.15 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.15 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 102.6 and Thunderbird 102.5 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SEAMONKEY-SPECIFIC CHANGES:
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug and link it to bug 1367257. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.
  • EXTENSIONS AND THEMES:
  • Extensions and Themes for SeaMonkey 2.53.15 can be installed from the SeaMonkey Add-Ons website or the "Get Add-Ons" section in the Add-ons Manager.
  • Extensions with binary components such as Enigmail only work for the specific platform they are released (e.g. win extension for Windows, linux64 for Linux 64 bits). Besides, matching version of extensions for SeaMonkey may not be the latest available of those versions. Therefore, they need to be adjusted for each new SeaMonkey release, which also means that an old version of such an add-on can break SeaMonkey if you disabled compatibility checking (which e.g. happens when you install the Add-on Compatibility Reporter add-on). Please, note the following warnings and advice regarding extensions:
  • Previous versions supported a proprietary JavaScript try/catch solution. This was removed in bug 1228841 and needed to be backported to 2.53.10b1. The backport might break some add-ons. One add-on affected is the classic version of DownThemAll. A fixed version is available from the DTA forked repo.
  • For Enigmail, please refer to the Enigmail page.
  • The latest supported version is 2.0.9 Enigmail but there have been some problems reported against it.
  • Adblock Plus 2.9.1 may cause huge memory and CPU consumption and is not recommended or officially supported in this SeaMonkey version. Consider switching to uBlock.
  • Lightbird 0.7.1. is not compatible with this version. The message preview pane will not update itself correctly.
  • The latest 1.16.x working version of uBlock can be found here. Please install the latest legacy version.
  • The latest working version of NoScript Classic 5.x can be found here.
  • Dictionaries in WebExtension formats do not work, even though they appear to install correctly. Support for them will be added at a later date. Please install the latest classic version from the dictionary history or unpack the dictionary inside the WebExtension package into your /dictionaries directory.
  • Lightweight themes are no longer provided on the SeaMonkey Add-ons site.
  • Full theme add-ons may need changes because of user interface and internal changes. If you find any problem with themes, contact the theme author. Before reporting a problem with the user interface please make sure to recreate it with either the Classic or Modern theme.
  • Because of security backports which removed obsolete code, Session Manager add-on version 0.8.1.14 or above is required to be compatible with current and future 2.53 releases.
  • KNOWN ISSUES:
  • This list covers some of the known problems with SeaMonkey 2.53.15. Please read this before reporting any new bugs.
  • The base user agent version was set to 68 in 2.53.10 to help with website compatibility. For YouTube do not set the user agent to identify only as Firefox or make sure you are using a site specific user agent for it. YouTube will show only a mostly blank page otherwise in some scenarios. Enhancements for this are planned in bug 1737436.
  • Some translations are missing in a few languages in the user interface and are being substituted with the corresponding US English terms. We plan to update the l10n translations for the final version but some languages like Polish are now missing a translator. Consider helping out with translations if you would like to have a 100% translated version.
  • Opening single new tabs from the Library always loads them in the foreground. The problem is tracked in bug 1619108
  • SeaMonkey will not start under Linux if you downloaded the wrong package.
  • We are providing x86 and x64 versions of SeaMonkey for Linux. For newer distributions you probably need the Linux x64 version.
  • Lightning or one of the distributed extensions is disabled under Add-ons.
  • Starting with SeaMonkey 2.53.7b1 the distributed extensions can no longer be removed. If you have previously enabled one then under some circumstance it might be disabled during the upgrade process. If the extension is disabled and can not be enabled then it is because an old or incompatible version is still present in your profile.
  • To clean out old versions use the following instructions:
  • Enter "about:config" in the location bar.
  • Enter "extensions.installedDistroAddon" in the search field.
  • Reset (delete) all keys found.
  • Open the Add-ons Manager. If the "remove" button is shown for the disabled extension use it. Stored data like your personal calendars will not be removed by this action.
  • Restart SeaMonkey.
  • Disable any distributed extension you do not wish to use.
  • Unable to connect to secure sites and a certificate error is shown.
  • In 99% of all cases this issue is caused by the same problem. Your antivirus software or custom firewall acts as a man in the middle and intercepts secure https traffic. In order to intercept and scan this encrypted network traffic, it normally uses a vendor specific certificate which is not installed by default in SeaMonkey by the third party software installer. If you want to keep this feature working you need to install one or more certificate(s) from the antivirus software in SeaMonkey. You need to ask your antivirus software vendor where they are located. Consult the SeaMonkey online help to find out how you can import and manage certificates.
  • If you experience a hang and/or get a message box warning that a script is busy when opening the Data Manager try deleting the webappsstore.* files from your profile folder when SeaMonkey is not running. These files contain data stored by websites and will be recreated during the next start. If you are unsure if the information is needed please back up the files before deleting them. The problem is tracked in bug 1305624 but so far no coding error has been found. This problem has been reported frequently when trying to manage passwords. But the problem will generally happen just after you open the Data Manager, because this component is also used for managing cookies, site preferences permissions and other settings.
  • If you are running Windows 7 "Send to > Mail recipient" might not work. More information can be found in bug 1356902. As a workaround install the "Microsoft Visual Studio 2015 to 2019" redistributable runtime library. For x86 install the VS2019 x86 runtime.
  • If you are using the x64 build install the VS2019 x64 runtime. SeaMonkey was built using the latest VS2019 compiler so make sure to upgrade any older VS2017 runtime.
  • If you experience a delay showing the first page after start, please delete the Safebrowsing folder in your profile. Bad Safebrowsing data may delay showing the first page for up to 30 seconds. The problem is tracked in bug 1432274. This can occur even if you are not using Safebrowsing because the lists are always fetched.
  • SeaMonkey does not currently support the WebExtensions add-on api. Some popular add-ons like NoScript and uBlock Origin are no longer shown because of this on the SeaMonkey add-ons website. You can usually get compatible versions from the manufacturers site. WebExtensions support is a planned feature for 2.57. For dictionaries please install the latest non webext version.
  • The SSL 3.0 encryption protocol is no longer supported due to security concerns (bug 1106470). Legacy websites may still rely on it and will not work with the newer TLS 1.x protocols. Contact the website administrator to update their server to resolve the issue at the source.
  • The Remember Passwords add-on breaks password handling. Please disable or uninstall this add-on using the Add-ons Manager.
  • You cannot set up a new Sync account or pair a device anymore (bug 998807).
  • Data loss warning: If you use a profile with this or any later version and then try to go back to SeaMonkey 2.49.5 or earlier, SeaMonkey will rename your bookmarks and history file to places.sqlite.corrupt and create a new places.sqlite file, effectively resetting your browsing history. This is because the internal format changed and the upgrade process only works in one direction. Additionally, running MailNews with local folders and POP3 mail filters may produce summary files that are not correctly read by previous versions of SeaMonkey. If you decide to go back to a previous version of SeaMonkey, you should do it from a profile backup only. Stored passwords and local storage will also be unavailable in the old version.
  • After creating a news account through clicking a news URL, the MailNews account wizard may be broken (the account type will always be News). To work around the problem, set the mail.server.serverX.valid pref (where X is the internal number of the corresponding news account) to true in about:config, or delete the invalid news account (bug 521861).
  • WebRTC has been disabled by default. It needs an add-on to enable it per site. See the webrtc-permissions-ui-toggle add-on.
  • Web pages may appear differently in the MailNews feed reader than in the browser (bug 662907). Workaround: Add a "noscript {display:none}" rule to your userContent.css (note that the Stylish add-on cannot be used here since it does not integrate with the MailNews feed reader).
  • Lightning keyboard shortcuts for accessing the calendar tab from within the MailNews window or from the main menu (Ctrl+Shift+C/D) do not work. (bug 514512).
  • If you try to start SeaMonkey using a locked profile, it will crash (see bug 573369).
  • In ChatZilla users are unable to add an exception for an invalid certificate unless an override is added to the preferences (see bug 1738597).
  • Linux:
  • SeaMonkey 2.53.7b1 can not be automatically updated to later beta versions as it is set to the wrong update channel. To overcome this, make sure SeaMonkey 2.53.7b1 is not running, edit the channel-prefs.js file located in the defaults/pref directory of the installation directory for SeaMonkey 2.53.7b1 and change the app.update.channel pref from "release" to "beta". When SeaMonkey is restarted it should then find future beta releases.
  • There is a race condition in libx11 causing applications to randomly abort on Ubuntu based distros (see bug 1743551 and bug 1782984).
  • Windows:
  • You might not be able to install SeaMonkey in Windows 10 if you have turned on the Windows Defender Smartscreen feature. Your SeaMonkey download will be blocked in the case. To overcome this go to "Windows Security->App & browser control" in the new Windows Settings and set the "Check apps and files" setting to Warn from Block.
  • Antivirus scanners may report that some parts of SeaMonkey (e.g. the file freebl3.dll) are suspicious. If you downloaded SeaMonkey from one of the official download sites, this is a false alarm. You might experience problems with secure websites when this happens. To fix the issue, instruct your antivirus software to ignore these files (and move them out of quarantine) and/or switch to another antivirus software and reinstall SeaMonkey.
  • Mac:
  • The scrollbar is not always visible on some websites under recent macOS versions (10.15 upwards) see bug 1684651.
  • You might not be able to install SeaMonkey under recent macOS versions. In this case please read Open a Mac app from an unidentified developer for a solution.
  • When hardware acceleration is off, background colors in the UI (toolbar, status bar etc.) might not update correctly when you switch focus from/to a window. Users running Macs with certain older hardware will experience this even if they haven't turned off hardware acceleration in Preferences (Appearance/Content) (bug 626096).
  • SeaMonkey 2.53.7b1 can not be automatically updated to later beta versions as it is set to the wrong update channel. To overcome this, make sure SeaMonkey 2.53.7b1 is not running, edit the channel-prefs.js file located in the Contents/Resources/defaults/pref folder of the installation folder for SeaMonkey 2.53.7b1 and change the app.update.channel pref from "release" to "beta". When SeaMonkey is restarted it should then find future beta releases.

New in SeaMonkey 2.53.15 Beta 1 (Dec 7, 2022)

  • 2.53.15 will be an incremental update on the 2.53.x branch and incorporates a number of enhancements, changes and fixes to the application as well as those from the underlying platform code.
  • We updated the SSL handling code (NSS) to Mozilla ESR102 level. The release also contains some minor updates for web compatibility like implementing microtasks. Improvements for filtering / tagging mails have been put in. Some changes have been made to the preferences and locale code handling so please test the add-ons that you have installed. This update also includes a fix for the crashes during startup on macOS 13 Ventura.
  • Before installing the new version make a full backup of your profile and thoroughly read and follow the Release Notes. We encourage testers to get involved in discussing and reporting problems as well as further improving the product.
  • SeaMonkey 2.53.15 Beta 1 is available in 23 languages, for Windows, macOS x64 and Linux.

New in SeaMonkey 2.53.14 (Sep 29, 2022)

  • SeaMonkey 2.53.14 contains (among other changes) the following major changes relative to SeaMonkey 2.53.13:
  • Updates to the following DOM HTML element interfaces: Embed, Object, Anchor, Area, Button, Frame, Canvas, IFrame, Link, Image, MenuItem, TextArea, Source, Select, Option, Script and Html. Please test add-ons.
  • Continue the switch from Python 2 to Python 3 in the build system.
  • Add ESR 102 links to debugQA bug 1779028.
  • Remove about plugins from help menu bug 1779031.
  • Remove url whitelist from SeaMonkey bug 1779037.
  • Dead links in cs_nav_prefs_advanced.xhtml [en-US] bug 1783558.
  • Dead links in cs_nav_prefs_advanced.xhtml bug 1786030.
  • Remove obsolete chat services from SeaMonkey address book bug 1779034.
  • Address Book: "Get Map" button is not shown for home addresses bug 1779319.
  • Added compatibility for rust 1.63
  • SeaMonkey 2.53.14 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.14 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.14 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 91.11 and Thunderbird 91.11 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.

New in SeaMonkey 2.53.14 Beta 1 (Aug 31, 2022)

  • SeaMonkey 2.53.14 contains (among other changes) the following major changes relative to SeaMonkey 2.53.13:
  • Updates to the following DOM HTML element interfaces: Embed, Object, Anchor, Area, Button, Frame, Canvas, IFrame, Link, Image, MenuItem, TextArea, Source, Select, Option, Script and Html. Please test add-ons.
  • Continue the switch from Python 2 to Python 3 in the build system.
  • Add ESR 102 links to debugQA bug 1779028.
  • Remove about plugins from help menu bug 1779031.
  • Dead links in cs_nav_prefs_advanced.xhtml [en-US] bug 1783558.
  • Dead links in cs_nav_prefs_advanced.xhtml bug 1786030.
  • Remove obsolete chat services from SeaMonkey address book bug 1779034.
  • Address Book: "Get Map" button is not shown for home addresses bug 1779319.
  • Added compatibility for rust 1.63
  • SeaMonkey 2.53.14 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.14 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.14 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 91.11 and Thunderbird 91.11 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SeaMonkey-specific changes:
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug and link it to bug 1367257. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.

New in SeaMonkey 2.53.13 (Jul 11, 2022)

  • SeaMonkey 2.53.13 contains (among other changes) the following major changes relative to SeaMonkey 2.53.12:
  • Updates to devtools.
  • Updates to build configuration.
  • Starting the switch from Python 2 to Python 3 in the build system.
  • Removal of array comprehensions, legacy iterators and generators bug 1414340 and bug 1098412.
  • Adding initial optional chaining and Promise.allSettled() support.
  • SeaMonkey 2.53.13 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.13 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.13 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 91.11 and Thunderbird 91.11 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SeaMonkey-specific changes:
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug and link it to bug 1367257. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.
  • Downloading:
  • The SeaMonkey project provides official versions and language packs of SeaMonkey 2.53.13 for Windows, Linux and macOS in US English and a small variety of other languages. Community volunteers are also contributing builds for other platforms. You can download SeaMonkey 2.53.13 here.
  • System Requirements, Installation and Uninstallation
  • Before installing, make sure your computer meets the system requirements.
  • Please note that the new Windows x64 version will only support Windows 7 x64 and up. You need to uninstall a previous Windows x86 version if you want to use it. Installing the x64 over the old x86 is not supported and does not remove the old version which might cause problems later.
  • SeaMonkey 2.53.13 will no longer offer to migrate your data from SeaMonkey 1.x or Mozilla 1.x at the first start after installation (bug 689437). In order to upgrade from such an old version, install the last SeaMonkey 2.0 release first, do the one-time profile upgrade, uninstall SeaMonkey 2.0 and then install your target release (e.g. this one).
  • If you are on an older release we suggest upgrading to SeaMonkey 2.49.5 first.
  • You can find more details about installation, profile data and uninstallation in our install and uninstall document.
  • Extensions (Add-ons) and Themes:
  • Extensions and Themes for SeaMonkey 2.53.13 can be installed from the SeaMonkey Add-Ons website or the "Get Add-Ons" section in the Add-ons Manager.
  • Extensions with binary components such as Enigmail only work for the specific platform they are released (e.g. win extension for Windows, linux64 for Linux 64 bits). Besides, matching version of extensions for SeaMonkey may not be the latest available of those versions. Therefore, they need to be adjusted for each new SeaMonkey release, which also means that an old version of such an add-on can break SeaMonkey if you disabled compatibility checking (which e.g. happens when you install the Add-on Compatibility Reporter add-on). Please, note the following warnings and advice regarding extensions:
  • Previous versions supported a proprietary JavaScript try/catch solution. This was removed in bug 1228841 and needed to be backported to 2.53.10b1. The backport might break some add-ons. One add-on affected is the classic version of DownThemAll. A fixed version is available from the DTA forked repo.
  • For Enigmail, please refer to the Enigmail page.
  • The latest supported version is 2.0.9 Enigmail but there have been some problems reported against it.
  • Adblock Plus 2.9.1 may cause huge memory and CPU consumption and is not recommended or officially supported in this SeaMonkey version. Consider switching to uBlock.
  • Lightbird 0.7.1. is not compatible with this version. The message preview pane will not update itself correctly.
  • The latest 1.16.x working version of uBlock can be found here. Please install the latest legacy version.
  • The latest working version of NoScript Classic 5.x can be found here.
  • Dictionaries in WebExtension formats do not work, even though they appear to install correctly. Support for them will be added at a later date. Please install the latest classic version from the dictionary history or unpack the dictionary inside the WebExtension package into your /dictionaries directory.
  • Lightweight themes are no longer provided on the SeaMonkey Add-ons site.
  • Full theme add-ons may need changes because of user interface and internal changes. If you find any problem with themes, contact the theme author. Before reporting a problem with the user interface please make sure to recreate it with either the Classic or Modern theme.
  • Because of security backports which removed obsolete code, Session Manager add-on version 0.8.1.14 or above is required to be compatible with current and future 2.53 releases.
  • Known Issues:
  • This list covers some of the known problems with SeaMonkey 2.53.13. Please read this before reporting any new bugs.
  • The base user agent version was set to 68 in 2.53.10 to help with website compatibility. For YouTube do not set the user agent to identify only as Firefox or make sure you are using a site specific user agent for it. YouTube will show only a mostly blank page otherwise in some scenarios. Enhancements for this are planned in bug 1737436.
  • Some translations are missing in a few languages in the user interface and are being substituted with the corresponding US English terms. We plan to update the l10n translations for the final version but some languages like Polish are now missing a translator. Consider helping out with translations if you would like to have a 100% translated version.
  • Opening single new tabs from the Library always loads them in the foreground. The problem is tracked in bug 1619108
  • SeaMonkey will not start under Linux if you downloaded the wrong package.
  • We are providing x86 and x64 versions of SeaMonkey for Linux. For newer distributions you probably need the Linux x64 version.
  • Lightning or one of the distributed extensions is disabled under Add-ons.
  • Starting with SeaMonkey 2.53.7b1 the distributed extensions can no longer be removed. If you have previously enabled one then under some circumstance it might be disabled during the upgrade process. If the extension is disabled and can not be enabled then it is because an old or incompatible version is still present in your profile.
  • To clean out old versions use the following instructions:
  • Enter "about:config" in the location bar.
  • Enter "extensions.installedDistroAddon" in the search field.
  • Reset (delete) all keys found.
  • Open the Add-ons Manager. If the "remove" button is shown for the disabled extension use it. Stored data like your personal calendars will not be removed by this action.
  • Restart SeaMonkey.
  • Disable any distributed extension you do not wish to use.
  • Unable to connect to secure sites and a certificate error is shown.
  • In 99% of all cases this issue is caused by the same problem. Your antivirus software or custom firewall acts as a man in the middle and intercepts secure https traffic. In order to intercept and scan this encrypted network traffic, it normally uses a vendor specific certificate which is not installed by default in SeaMonkey by the third party software installer. If you want to keep this feature working you need to install one or more certificate(s) from the antivirus software in SeaMonkey. You need to ask your antivirus software vendor where they are located. Consult the SeaMonkey online help to find out how you can import and manage certificates.
  • If you experience a hang and/or get a message box warning that a script is busy when opening the Data Manager try deleting the webappsstore.* files from your profile folder when SeaMonkey is not running. These files contain data stored by websites and will be recreated during the next start. If you are unsure if the information is needed please back up the files before deleting them. The problem is tracked in bug 1305624 but so far no coding error has been found. This problem has been reported frequently when trying to manage passwords. But the problem will generally happen just after you open the Data Manager, because this component is also used for managing cookies, site preferences permissions and other settings.
  • If you are running Windows 7 "Send to > Mail recipient" might not work. More information can be found in bug 1356902. As a workaround install the "Microsoft Visual Studio 2015 to 2019" redistributable runtime library. For x86 install the VS2019 x86 runtime.
  • If you are using the x64 build install the VS2019 x64 runtime. SeaMonkey was built using the latest VS2019 compiler so make sure to upgrade any older VS2017 runtime.
  • If you experience a delay showing the first page after start, please delete the Safebrowsing folder in your profile. Bad Safebrowsing data may delay showing the first page for up to 30 seconds. The problem is tracked in bug 1432274. This can occur even if you are not using Safebrowsing because the lists are always fetched.
  • SeaMonkey does not currently support the WebExtensions add-on api. Some popular add-ons like NoScript and uBlock Origin are no longer shown because of this on the SeaMonkey add-ons website. You can usually get compatible versions from the manufacturers site. WebExtensions support is a planned feature for 2.57. For dictionaries please install the latest non webext version.
  • The SSL 3.0 encryption protocol is no longer supported due to security concerns (bug 1106470). Legacy websites may still rely on it and will not work with the newer TLS 1.x protocols. Contact the website administrator to update their server to resolve the issue at the source.
  • The Remember Passwords add-on breaks password handling. Please disable or uninstall this add-on using the Add-ons Manager.
  • You cannot set up a new Sync account or pair a device anymore (bug 998807).
  • Data loss warning: If you use a profile with this or any later version and then try to go back to SeaMonkey 2.49.5 or earlier, SeaMonkey will rename your bookmarks and history file to places.sqlite.corrupt and create a new places.sqlite file, effectively resetting your browsing history. This is because the internal format changed and the upgrade process only works in one direction. Additionally, running MailNews with local folders and POP3 mail filters may produce summary files that are not correctly read by previous versions of SeaMonkey. If you decide to go back to a previous version of SeaMonkey, you should do it from a profile backup only. Stored passwords and local storage will also be unavailable in the old version.
  • After creating a news account through clicking a news URL, the MailNews account wizard may be broken (the account type will always be News). To work around the problem, set the mail.server.serverX.valid pref (where X is the internal number of the corresponding news account) to true in about:config, or delete the invalid news account (bug 521861).
  • WebRTC has been disabled by default. It needs an add-on to enable it per site. See the webrtc-permissions-ui-toggle add-on.
  • Web pages may appear differently in the MailNews feed reader than in the browser (bug 662907). Workaround: Add a "noscript {display:none}" rule to your userContent.css (note that the Stylish add-on cannot be used here since it does not integrate with the MailNews feed reader).
  • Lightning keyboard shortcuts for accessing the calendar tab from within the MailNews window or from the main menu (Ctrl+Shift+C/D) do not work. (bug 514512).
  • If you try to start SeaMonkey using a locked profile, it will crash (see bug 573369).
  • In ChatZilla users are unable to add an exception for an invalid certificate unless an override is added to the preferences (see bug 1738597).
  • Linux:
  • SeaMonkey 2.53.7b1 can not be automatically updated to later beta versions as it is set to the wrong update channel. To overcome this, make sure SeaMonkey 2.53.7b1 is not running, edit the channel-prefs.js file located in the defaults/pref directory of the installation directory for SeaMonkey 2.53.7b1 and change the app.update.channel pref from "release" to "beta". When SeaMonkey is restarted it should then find future beta releases.
  • There is a race condition in libx11 causing applications to randomly abort on Ubuntu based distros (see bug 1743551 and bug 1782984).
  • Windows:
  • You might not be able to install SeaMonkey in Windows 10 if you have turned on the Windows Defender Smartscreen feature. Your SeaMonkey download will be blocked in the case. To overcome this go to "Windows Security->App & browser control" in the new Windows Settings and set the "Check apps and files" setting to Warn from Block.
  • Antivirus scanners may report that some parts of SeaMonkey (e.g. the file freebl3.dll) are suspicious. If you downloaded SeaMonkey from one of the official download sites, this is a false alarm. You might experience problems with secure websites when this happens. To fix the issue, instruct your antivirus software to ignore these files (and move them out of quarantine) and/or switch to another antivirus software and reinstall SeaMonkey.
  • Mac:
  • The scrollbar is not always visible on some websites under recent macOS versions (10.15 upwards) see bug 1684651.
  • You might not be able to install SeaMonkey under recent macOS versions. In this case please read Open a Mac app from an unidentified developer for a solution.
  • When hardware acceleration is off, background colors in the UI (toolbar, status bar etc.) might not update correctly when you switch focus from/to a window. Users running Macs with certain older hardware will experience this even if they haven't turned off hardware acceleration in Preferences (Appearance/Content) (bug 626096).
  • SeaMonkey 2.53.7b1 can not be automatically updated to later beta versions as it is set to the wrong update channel. To overcome this, make sure SeaMonkey 2.53.7b1 is not running, edit the channel-prefs.js file located in the Contents/Resources/defaults/pref folder of the installation folder for SeaMonkey 2.53.7b1 and change the app.update.channel pref from "release" to "beta". When SeaMonkey is restarted it should then find future beta releases.
  • Troubleshooting:
  • Some questions are asked more frequently than others. Have a look at the SeaMonkey FAQ. Maybe your particular problem has already been solved.
  • Some antivirus software keeps detecting our installers as containing a "Trojan" or "Downloader". This is a false positive because of some wrong detection mechanism in the antivirus software. The code in question is actually from 7-Zip and decompresses the installer so that its contents can run and install SeaMonkey. That technology is widely used and probably can be used to compress bad as well as good software, but the 7-Zip code itself is perfectly safe. Mozilla scans all our files routinely when putting them on the FTP server and we assure you that our installers are as clean as the official Firefox downloads that are scanned by the same mechanisms.
  • For security, parts of bug 1035091 were ported in bug 1411708. This might cause problems with add-ons like Stylish which use moz-document. Set the preference "layout.css.moz-document.content.enabled" to "true" to overcome this but be aware that this disables the added security fix.
  • Poorly designed or incompatible extensions can cause problems with SeaMonkey, including make it crash, slow down page display, etc. If you encounter strange problems relating to parts of SeaMonkey no longer working, the browser not starting, windows with strange or distorted appearance, degraded performance, etc, you may be suffering from Extension or Theme trouble. Restart SeaMonkey in Safe Mode. On Windows, start using the "Safe Mode" shortcut created in your Start menu or by running seamonkey.exe -safe-mode. On Linux, start with /path-to-seamonkey/seamonkey -safe-mode or first change to the SeaMonkey installation directory and start with ./seamonkey -safe-mode, and on macOS, run:
  • cd /Applications/SeaMonkey.app/Contents/MacOS/
  • ./seamonkey-bin -safe-mode
  • When started in Safe Mode all extensions are disabled and the Default theme is used. Disable the Extension/Theme that is causing trouble and then start normally.
  • If you uninstall an extension that is installed with your user profile (i.e. you installed it from a Web page) and then wish to install it for all user profiles using the -install-global-extension command line flag, you must restart SeaMonkey once to cleanse the profile extensions datasource of traces of that extension before installing with the switch. If you do not do this you may end up with a jammed entry in the Extensions list and will be unable to install the extension globally.
  • If you encounter strange problems relating to bookmarks, downloads, window placement, toolbars, history, or other settings, it is recommended that you try creating a new profile and attempting to reproduce the problem before filing bugs. Create a new profile by running SeaMonkey with the -P command line argument, choose the "Manage Profiles" button and then choose "Create Profile...". Migrate your settings files (Bookmarks, Saved Passwords, etc) over one by one, checking each time to see if the problems resurface. If you do find a particular profile data file is causing a problem, file a bug and attach the file.

New in SeaMonkey 2.53.13 Beta 1 (Jun 18, 2022)

  • SeaMonkey 2.53.13 contains (among other changes) the following major changes relative to SeaMonkey 2.53.12:
  • Updates to devtoos.
  • Updates to build configuration.
  • Starting the switch from Python 2 to Python 3 in the build system.
  • Removal of array comprehensions, legacy iterators and generators bug 1414340 and bug 1098412.
  • Adding initial optional chaining and Promise.allSettled() support.
  • SeaMonkey 2.53.13 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.13 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.13 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 91.10 and Thunderbird 91.10 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SeaMonkey-specific changes:
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug and link it to bug 1367257. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.

New in SeaMonkey 2.53.12 (May 5, 2022)

  • SeaMonkey 2.53.12 contains (among other changes) the following major changes relative to SeaMonkey 2.53.11.1:
  • Format Toolbar forgets its hidden status when switching to other view modes bug 1719020.
  • Remove obsolete plugin code from SeaMonkey bug 1762733.
  • Fix a few strict warnings in SeaMonkey bug 1755553.
  • Remove Run Flash from Site permissions and page info bug 1758289.
  • Use fixIterator and replace use of removeItemAt in FilterListDialog bug 1756359.
  • Remove RDF usage in tabmail.js bug 1758282.
  • Implement 'Edit Template' and 'New Message From Template' commands and UI bug 1759376.
  • [SM] Implement 'Edit Draft' command and hide it when not in a draft folder (port Thunderbird bug 1106412) bug 1256716.
  • Messages in Template folder need "Edit Template" button in header (like for Drafts) bug 80280.
  • Refactor and simplify the feed Subscribe dialog options updates bug 1420473.
  • Add system memory and disk size and placeDB page limit to about:support bug 1753729.
  • The following bugs were fixed in our branch of the Gecko source code only:
  • Remove warning about missing plugins in SeaMonkey 2.53 and 2.57 bug 1755558.
  • SeaMonkey 2.53.12 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.12 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.12 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 91.9 and Thunderbird 91.9 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • Extensions (Add-ons) and Themes:
  • Extensions and Themes for SeaMonkey 2.53.12 can be installed from the SeaMonkey Add-Ons website or the "Get Add-Ons" section in the Add-ons Manager.
  • Extensions with binary components such as Enigmail only work for the specific platform they are released (e.g. win extension for Windows, linux64 for Linux 64 bits). Besides, matching version of extensions for SeaMonkey may not be the latest available of those versions. Therefore, they need to be adjusted for each new SeaMonkey release, which also means that an old version of such an add-on can break SeaMonkey if you disabled compatibility checking (which e.g. happens when you install the Add-on Compatibility Reporter add-on). Please, note the following warnings and advice regarding extensions:
  • Previous versions supported a proprietary JavaScript try/catch solution. This was removed in bug 1228841 and needed to be backported to 2.53.10b1. The backport might break some add-ons. One add-on affected is the classic version of DownThemAll. A fixed version is available from the DTA forked repo.
  • For Enigmail, please refer to the Enigmail page.
  • The latest supported version is 2.0.9 Enigmail but there have been some problems reported against it.
  • Adblock Plus 2.9.1 may cause huge memory and CPU consumption and is not recommended or officially supported in this SeaMonkey version. Consider switching to uBlock.
  • Lightbird 0.7.1. is not compatible with this version. The message preview pane will not update itself correctly.
  • The latest 1.16.x working version of uBlock can be found here. Please install the latest legacy version.
  • The latest working version of NoScript Classic 5.x can be found here.
  • Dictionaries in WebExtension formats do not work, even though they appear to install correctly. Support for them will be added at a later date. Please install the latest classic version from the dictionary history or unpack the dictionary inside the WebExtension package into your /dictionaries directory.
  • Lightweight themes are no longer provided on the SeaMonkey Add-ons site.
  • Full theme add-ons may need changes because of user interface and internal changes. If you find any problem with themes, contact the theme author. Before reporting a problem with the user interface please make sure to recreate it with either the Classic or Modern theme.
  • Because of security backports which removed obsolete code, Session Manager add-on version 0.8.1.14 or above is required to be compatible with current and future 2.53 releases.

New in SeaMonkey 2.53.12 Beta 1 (Apr 27, 2022)

  • SeaMonkey 2.53.12 contains (among other changes) the following major changes relative to SeaMonkey 2.53.11.1:
  • Format Toolbar forgets its hidden status when switching to other view modes bug 1719020.
  • Remove obsolete plugin code from SeaMonkey bug 1762733.
  • Fix a few strict warnings in SeaMonkey bug 1755553.
  • Remove Run Flash from Site permissions and page info bug 1758289.
  • Use fixIterator and replace use of removeItemAt in FilterListDialog bug 1756359.
  • Remove RDF usage in tabmail.js bug 1758282.
  • Implement 'Edit Template' and 'New Message From Template' commands and UI bug 1759376.
  • [SM] Implement 'Edit Draft' command and hide it when not in a draft folder (port Thunderbird bug 1106412) bug 1256716.
  • Messages in Template folder need "Edit Template" button in header (like for Drafts) bug 80280.
  • Refactor and simplify the feed Subscribe dialog options updates bug 1420473.
  • Add system memory and disk size and placeDB page limit to about:support bug 1753729.
  • The following bugs were fixed in our branch of the Gecko source code only:
  • Remove warning about missing plugins in SeaMonkey 2.53 and 2.57 bug 1755558.
  • SeaMonkey 2.53.12 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.12 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.12 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 91.8 and Thunderbird 91.8 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SeaMonkey-specific changes:
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug and link it to bug 1367257. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.
  • Downloading:
  • The SeaMonkey project provides official versions and language packs of SeaMonkey 2.53.12 Beta 1 for Windows, Linux and macOS in US English and a small variety of other languages. Community volunteers are also contributing builds for other platforms. You can download SeaMonkey 2.53.12 Beta 1 here.
  • System Requirements, Installation and Uninstallation
  • Before installing, make sure your computer meets the system requirements.
  • Please note that the new Windows x64 version will only support Windows 7 x64 and up. You need to uninstall a previous Windows x86 version if you want to use it. Installing the x64 over the old x86 is not supported and does not remove the old version which might cause problems later.
  • SeaMonkey 2.53.12 Beta 1 will no longer offer to migrate your data from SeaMonkey 1.x or Mozilla 1.x at the first start after installation (bug 689437). In order to upgrade from such an old version, install the last SeaMonkey 2.0 release first, do the one-time profile upgrade, uninstall SeaMonkey 2.0 and then install your target release (e.g. this one).
  • If you are on an older release we suggest upgrading to SeaMonkey 2.49.5 first.
  • You can find more details about installation, profile data and uninstallation in our install and uninstall document.
  • Extensions (Add-ons) and Themes:
  • Extensions and Themes for SeaMonkey 2.53.12 Beta 1 can be installed from the SeaMonkey Add-Ons website or the "Get Add-Ons" section in the Add-ons Manager.
  • Extensions with binary components such as Enigmail only work for the specific platform they are released (e.g. win extension for Windows, linux64 for Linux 64 bits). Besides, matching version of extensions for SeaMonkey may not be the latest available of those versions. Therefore, they need to be adjusted for each new SeaMonkey release, which also means that an old version of such an add-on can break SeaMonkey if you disabled compatibility checking (which e.g. happens when you install the Add-on Compatibility Reporter add-on). Please, note the following warnings and advice regarding extensions:
  • Previous versions supported a proprietary JavaScript try/catch solution. This was removed in bug 1228841 and needed to be backported to 2.53.10b1. The backport might break some add-ons. One add-on affected is the classic version of DownThemAll. A fixed version is available from the DTA forked repo.
  • For Enigmail, please refer to the Enigmail page.
  • The latest supported version is 2.0.9 Enigmail but there have been some problems reported against it.
  • Adblock Plus 2.9.1 may cause huge memory and CPU consumption and is not recommended or officially supported in this SeaMonkey version. Consider switching to uBlock.
  • Lightbird 0.7.1. is not compatible with this version. The message preview pane will not update itself correctly.
  • The latest 1.16.x working version of uBlock can be found here. Please install the latest legacy version.
  • The latest working version of NoScript Classic 5.x can be found here.
  • Dictionaries in WebExtension formats do not work, even though they appear to install correctly. Support for them will be added at a later date. Please install the latest classic version from the dictionary history or unpack the dictionary inside the WebExtension package into your /dictionaries directory.
  • Lightweight themes are no longer provided on the SeaMonkey Add-ons site.
  • Full theme add-ons may need changes because of user interface and internal changes. If you find any problem with themes, contact the theme author. Before reporting a problem with the user interface please make sure to recreate it with either the Classic or Modern theme.
  • Because of security backports which removed obsolete code, Session Manager add-on version 0.8.1.14 or above is required to be compatible with current and future 2.53 releases.
  • Known Issues:
  • This list covers some of the known problems with SeaMonkey 2.53.12 Beta 1. Please read this before reporting any new bugs.
  • The base user agent version was set to 68 in 2.53.10 to help with website compatibility. For YouTube do not set the user agent to identify only as Firefox or make sure you are using a site specific user agent for it. YouTube will show only a mostly blank page otherwise in some scenarios. Enhancements for this are planned in bug 1737436.
  • Some translations are missing in a few languages in the user interface and are being substituted with the corresponding US English terms. We plan to update the l10n translations for the final version but some languages like Polish are now missing a translator. Consider helping out with translations if you would like to have a 100% translated version.
  • Opening single new tabs from the Library always loads them in the foreground. The problem is tracked in bug 1619108
  • SeaMonkey will not start under Linux if you downloaded the wrong package.
  • We are providing x86 and x64 versions of SeaMonkey for Linux. For newer distributions you probably need the Linux x64 version.
  • Lightning or one of the distributed extensions is disabled under Add-ons.
  • Starting with SeaMonkey 2.53.7b1 the distributed extensions can no longer be removed. If you have previously enabled one then under some circumstance it might be disabled during the upgrade process. If the extension is disabled and can not be enabled then it is because an old or incompatible version is still present in your profile.
  • To clean out old versions use the following instructions:
  • Enter "about:config" in the location bar.
  • Enter "extensions.installedDistroAddon" in the search field.
  • Reset (delete) all keys found.
  • Open the Add-ons Manager. If the "remove" button is shown for the disabled extension use it. Stored data like your personal calendars will not be removed by this action.
  • Restart SeaMonkey.
  • Disable any distributed extension you do not wish to use.
  • Unable to connect to secure sites and a certificate error is shown.
  • In 99% of all cases this issue is caused by the same problem. Your antivirus software or custom firewall acts as a man in the middle and intercepts secure https traffic. In order to intercept and scan this encrypted network traffic, it normally uses a vendor specific certificate which is not installed by default in SeaMonkey by the third party software installer. If you want to keep this feature working you need to install one or more certificate(s) from the antivirus software in SeaMonkey. You need to ask your antivirus software vendor where they are located. Consult the SeaMonkey online help to find out how you can import and manage certificates.
  • If you experience a hang and/or get a message box warning that a script is busy when opening the Data Manager try deleting the webappsstore.* files from your profile folder when SeaMonkey is not running. These files contain data stored by websites and will be recreated during the next start. If you are unsure if the information is needed please back up the files before deleting them. The problem is tracked in bug 1305624 but so far no coding error has been found. This problem has been reported frequently when trying to manage passwords. But the problem will generally happen just after you open the Data Manager, because this component is also used for managing cookies, site preferences permissions and other settings.
  • If you are running Windows 7 "Send to > Mail recipient" might not work. More information can be found in bug 1356902. As a workaround install the "Microsoft Visual Studio 2015 to 2019" redistributable runtime library. For x86 install the VS2019 x86 runtime.
  • If you are using the x64 build install the VS2019 x64 runtime. SeaMonkey was built using the latest VS2019 compiler so make sure to upgrade any older VS2017 runtime.
  • If you experience a delay showing the first page after start, please delete the Safebrowsing folder in your profile. Bad Safebrowsing data may delay showing the first page for up to 30 seconds. The problem is tracked in bug 1432274. This can occur even if you are not using Safebrowsing because the lists are always fetched.
  • SeaMonkey does not currently support the WebExtensions add-on api. Some popular add-ons like NoScript and uBlock Origin are no longer shown because of this on the SeaMonkey add-ons website. You can usually get compatible versions from the manufacturers site. WebExtensions support is a planned feature for 2.57. For dictionaries please install the latest non webext version.
  • The SSL 3.0 encryption protocol is no longer supported due to security concerns (bug 1106470). Legacy websites may still rely on it and will not work with the newer TLS 1.x protocols. Contact the website administrator to update their server to resolve the issue at the source.
  • The Remember Passwords add-on breaks password handling. Please disable or uninstall this add-on using the Add-ons Manager.
  • You cannot set up a new Sync account or pair a device anymore (bug 998807).
  • Data loss warning: If you use a profile with this or any later version and then try to go back to SeaMonkey 2.49.5 or earlier, SeaMonkey will rename your bookmarks and history file to places.sqlite.corrupt and create a new places.sqlite file, effectively resetting your browsing history. This is because the internal format changed and the upgrade process only works in one direction. Additionally, running MailNews with local folders and POP3 mail filters may produce summary files that are not correctly read by previous versions of SeaMonkey. If you decide to go back to a previous version of SeaMonkey, you should do it from a profile backup only. Stored passwords and local storage will also be unavailable in the old version.
  • After creating a news account through clicking a news URL, the MailNews account wizard may be broken (the account type will always be News). To work around the problem, set the mail.server.serverX.valid pref (where X is the internal number of the corresponding news account) to true in about:config, or delete the invalid news account (bug 521861).
  • WebRTC has been disabled by default. It needs an add-on to enable it per site. See the webrtc-permissions-ui-toggle add-on.
  • Web pages may appear differently in the MailNews feed reader than in the browser (bug 662907). Workaround: Add a "noscript {display:none}" rule to your userContent.css (note that the Stylish add-on cannot be used here since it does not integrate with the MailNews feed reader).
  • Lightning keyboard shortcuts for accessing the calendar tab from within the MailNews window or from the main menu (Ctrl+Shift+C/D) do not work. (bug 514512).
  • If you try to start SeaMonkey using a locked profile, it will crash (see bug 573369).
  • In ChatZilla users are unable to add an exception for an invalid certificate unless an override is added to the preferences (see bug 1738597).
  • Linux:
  • SeaMonkey 2.53.7b1 can not be automatically updated to later beta versions as it is set to the wrong update channel. To overcome this, make sure SeaMonkey 2.53.7b1 is not running, edit the channel-prefs.js file located in the defaults/pref directory of the installation directory for SeaMonkey 2.53.7b1 and change the app.update.channel pref from "release" to "beta". When SeaMonkey is restarted it should then find future beta releases.
  • There is a race condition in libx11 causing applications to randomly abort on Ubuntu based distros (see bug 1743551 and bug 1782984).
  • Windows:
  • You might not be able to install SeaMonkey in Windows 10 if you have turned on the Windows Defender Smartscreen feature. Your SeaMonkey download will be blocked in the case. To overcome this go to "Windows Security->App & browser control" in the new Windows Settings and set the "Check apps and files" setting to Warn from Block.
  • Antivirus scanners may report that some parts of SeaMonkey (e.g. the file freebl3.dll) are suspicious. If you downloaded SeaMonkey from one of the official download sites, this is a false alarm. You might experience problems with secure websites when this happens. To fix the issue, instruct your antivirus software to ignore these files (and move them out of quarantine) and/or switch to another antivirus software and reinstall SeaMonkey.
  • Mac:
  • The scrollbar is not always visible on some websites under recent macOS versions (10.15 upwards) see bug 1684651.
  • You might not be able to install SeaMonkey under recent macOS versions. In this case please read Open a Mac app from an unidentified developer for a solution.
  • When hardware acceleration is off, background colors in the UI (toolbar, status bar etc.) might not update correctly when you switch focus from/to a window. Users running Macs with certain older hardware will experience this even if they haven't turned off hardware acceleration in Preferences (Appearance/Content) (bug 626096).
  • SeaMonkey 2.53.7b1 can not be automatically updated to later beta versions as it is set to the wrong update channel. To overcome this, make sure SeaMonkey 2.53.7b1 is not running, edit the channel-prefs.js file located in the Contents/Resources/defaults/pref folder of the installation folder for SeaMonkey 2.53.7b1 and change the app.update.channel pref from "release" to "beta". When SeaMonkey is restarted it should then find future beta releases.
  • Troubleshooting:
  • Some questions are asked more frequently than others. Have a look at the SeaMonkey FAQ. Maybe your particular problem has already been solved.
  • Some antivirus software keeps detecting our installers as containing a "Trojan" or "Downloader". This is a false positive because of some wrong detection mechanism in the antivirus software. The code in question is actually from 7-Zip and decompresses the installer so that its contents can run and install SeaMonkey. That technology is widely used and probably can be used to compress bad as well as good software, but the 7-Zip code itself is perfectly safe. Mozilla scans all our files routinely when putting them on the FTP server and we assure you that our installers are as clean as the official Firefox downloads that are scanned by the same mechanisms.
  • For security, parts of bug 1035091 were ported in bug 1411708. This might cause problems with add-ons like Stylish which use moz-document. Set the preference "layout.css.moz-document.content.enabled" to "true" to overcome this but be aware that this disables the added security fix.
  • Poorly designed or incompatible extensions can cause problems with SeaMonkey, including make it crash, slow down page display, etc. If you encounter strange problems relating to parts of SeaMonkey no longer working, the browser not starting, windows with strange or distorted appearance, degraded performance, etc, you may be suffering from Extension or Theme trouble. Restart SeaMonkey in Safe Mode. On Windows, start using the "Safe Mode" shortcut created in your Start menu or by running seamonkey.exe -safe-mode. On Linux, start with /path-to-seamonkey/seamonkey -safe-mode or first change to the SeaMonkey installation directory and start with ./seamonkey -safe-mode, and on macOS, run:
  • cd /Applications/SeaMonkey.app/Contents/MacOS/
  • ./seamonkey-bin -safe-mode
  • When started in Safe Mode all extensions are disabled and the Default theme is used. Disable the Extension/Theme that is causing trouble and then start normally.
  • If you uninstall an extension that is installed with your user profile (i.e. you installed it from a Web page) and then wish to install it for all user profiles using the -install-global-extension command line flag, you must restart SeaMonkey once to cleanse the profile extensions datasource of traces of that extension before installing with the switch. If you do not do this you may end up with a jammed entry in the Extensions list and will be unable to install the extension globally.
  • If you encounter strange problems relating to bookmarks, downloads, window placement, toolbars, history, or other settings, it is recommended that you try creating a new profile and attempting to reproduce the problem before filing bugs. Create a new profile by running SeaMonkey with the -P command line argument, choose the "Manage Profiles" button and then choose "Create Profile...". Migrate your settings files (Bookmarks, Saved Passwords, etc) over one by one, checking each time to see if the problems resurface. If you do find a particular profile data file is causing a problem, file a bug and attach the file.

New in SeaMonkey 2.53.11.1 (Mar 31, 2022)

  • SeaMonkey 2.53.11.1 contains (among other changes) the following changes relative to SeaMonkey 2.53.11:
  • Fix edge case when setting IntersectionObserver threshold bug 1758291.
  • OAuth2 prefs should use realuserName instead of username bug 1518126.
  • SeaMonkey 2.53.11.1 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.11.1 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.11.1 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.8.0 release notes for specific security fixes in this release.
  • Additional important security fixes up to Current Firefox 91.7 and Thunderbird 91.7 ESR plus many enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SeaMonkey-specific changes:
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug and link it to bug 1367257. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.
  • Downloading:
  • The SeaMonkey project provides official versions and language packs of SeaMonkey 2.53.11.1 for Windows, Linux and macOS in US English and a small variety of other languages. Community volunteers are also contributing builds for other platforms. You can download SeaMonkey 2.53.11.1 here.
  • System Requirements, Installation and Uninstallation:
  • Before installing, make sure your computer meets the system requirements.
  • Please note that the new Windows x64 version will only support Windows 7 x64 and up. You need to uninstall a previous Windows x86 version if you want to use it. Installing the x64 over the old x86 is not supported and does not remove the old version which might cause problems later.
  • SeaMonkey 2.53.11.1 will no longer offer to migrate your data from SeaMonkey 1.x or Mozilla 1.x at the first start after installation (bug 689437). In order to upgrade from such an old version, install the last SeaMonkey 2.0 release first, do the one-time profile upgrade, uninstall SeaMonkey 2.0 and then install your target release (e.g. this one).
  • If you are on an older release we suggest upgrading to SeaMonkey 2.49.5 first.
  • You can find more details about installation, profile data and uninstallation in our install and uninstall document.
  • Extensions (Add-ons) and Themes:
  • Extensions and Themes for SeaMonkey 2.53.11.1 can be installed from the SeaMonkey Add-Ons website or the "Get Add-Ons" section in the Add-ons Manager.
  • Extensions with binary components such as Enigmail only work for the specific platform they are released (e.g. win extension for Windows, linux64 for Linux 64 bits). Besides, matching version of extensions for SeaMonkey may not be the latest available of those versions. Therefore, they need to be adjusted for each new SeaMonkey release, which also means that an old version of such an add-on can break SeaMonkey if you disabled compatibility checking (which e.g. happens when you install the Add-on Compatibility Reporter add-on).
  • Previous versions supported a proprietary JavaScript try/catch solution. This was removed in bug 1228841 and needed to be backported to 2.53.10b1. The backport might break some add-ons. One add-on affected is the classic version of DownThemAll. A fixed version is available from the DTA forked repo.
  • For Enigmail, please refer to the Enigmail page.
  • The latest supported version is 2.0.9 Enigmail but there have been some problems reported against it.
  • Adblock Plus 2.9.1 may cause huge memory and CPU consumption and is not recommended or officially supported in this SeaMonkey version. Consider switching to uBlock.
  • Lightbird 0.7.1. is not compatible with this version. The message preview pane will not update itself correctly.
  • The latest 1.16.x working version of uBlock can be found here. Please install the latest legacy version.
  • The latest working version of NoScript Classic 5.x can be found here.
  • Dictionaries in WebExtension formats do not work, even though they appear to install correctly. Support for them will be added at a later date. Please install the latest classic version from the dictionary history or unpack the dictionary inside the WebExtension package into your /dictionaries directory.
  • Lightweight themes are no longer provided on the SeaMonkey Add-ons site.
  • Full theme add-ons may need changes because of user interface and internal changes. If you find any problem with themes, contact the theme author. Before reporting a problem with the user interface please make sure to recreate it with either the Classic or Modern theme.
  • Because of security backports which removed obsolete code, Session Manager add-on version 0.8.1.14 or above is required to be compatible with current and future 2.53 releases.

New in SeaMonkey 2.53.11 (Mar 2, 2022)

  • CHANGES:
  • Remove obsolete MOZ_EXTENSIONS check in suite bug 1749146.
  • Add connect button to cZ Networks Editor bug 1736443.
  • Remove freenode remnants from ChatZilla in SeaMonkey bug 1741082.
  • Prefer secure over insecure protocol in network list in ChatZilla bug 1744440.
  • Composer - Change tag textbox is not removed after use bug 1755369.
  • Clean up repo links in debugQA bug 1746790.
  • Fix misspelled references to macOS in suite bug 1749144.
  • Remove obsolete references to Java and Flash bug 1749141.
  • Help button not working in delete cert dialog bug 1750386.
  • Rearrange Message Filter Dialog to make room for new features bug 1735053.
  • Use Insert key as shortcut to create new message filters bug 1735055.
  • Rename some variables used in SeaMonkey's FilterListDialog to match Thunderbird's bug 1735056.
  • Implement Copy to New message filter functionality bug 1735057.
  • Add move to top / bottom buttons to message filters bug 1735059.
  • Add preference to not prompt for message filter deletion bug 1735061.
  • Clean up folder handling in FilterListDialog bug 1736425.
  • Add refresh function to Filter list dialog so that it can be updated when already open and new filters are added externally bug 1737450.
  • Use listbox rather than tree in FilterListDialog bug 1746081.
  • MsgFilterList(args) should take targetFilter and pass it to FilterListDialog bug 1753891.
  • Mail&News' start.xhtml: "We" link broken bug 1748178.
  • Add search functionality to filter dialog bug 1749207.
  • Move the taskbar refresh timer in SeaMonkey to idle dispatch bug 1746788.
  • Prevent subresource loads from showing the progress indicator on the tab in SeaMonkey bug 1746787.
  • SeaMonkey-specific changes:
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug and link it to bug 1367257. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.

New in SeaMonkey 2.53.11 Beta 1 (Jan 31, 2022)

  • Remove obsolete MOZ_EXTENSIONS check in suite bug 1749146.
  • Add connect button to cZ Networks Editor bug 1736443.
  • Remove freenode remnants from ChatZilla in SeaMonkey bug 1741082.
  • Prefer secure over insecure protocol in network list in ChatZilla bug 1744440.
  • Clean up repo links in debugQA bug 1746790.
  • Fix misspelled references to macOS in suite bug 1749144.
  • Remove obsolete references to Java and Flash bug 1749141.
  • Help button not working in delete cert dialog bug 1750386.
  • Rearrange Message Filter Dialog to make room for new features bug 1735053.
  • Use Insert key as shortcut to create new message filters bug 1735055.
  • Rename some variables used in SeaMonkey's FilterListDialog to match Thunderbird's bug 1735056.
  • Implement Copy to New message filter functionality bug 1735057.
  • Add move to top / bottom buttons to message filters bug 1735059.
  • Add preference to not prompt for message filter deletion bug 1735061.
  • Clean up folder handling in FilterListDialog bug 1736425.
  • Add refresh function to Filter list dialog so that it can be updated when already open and new filters are added externally bug 1737450.
  • Use listbox rather than tree in FilterListDialog bug 1746081.
  • Mail&News' start.xhtml: "We" link broken bug 1748178.
  • Add search functionality to filter dialog bug 1749207.
  • Move the taskbar refresh timer in SeaMonkey to idle dispatch bug 1746788.
  • Prevent subresource loads from showing the progress indicator on the tab in SeaMonkey bug 1746787.

New in SeaMonkey 2.53.10.2 (Jan 3, 2022)

  • SeaMonkey 2.53.10.2 contains (among other changes) the following major changes relative to SeaMonkey 2.53.10.1:
  • Obtain Windows code-signing certificate for SeaMonkey binary and update signing bug 1438084.
  • Support SHA-2 hashes in CertIDs in OCSP responses - port of bug 1746221.
  • The following bugs were fixed in our branch of the Gecko source code only:
  • Fix rust 1.57 Windows linking for SeaMonkey 2.53 bug 1746785.
  • SeaMonkey 2.53.10.2 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.10.2 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • Additional important security fixes up to Current Firefox 91.4.1 ESR and a few enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SeaMonkey 2.53.10.2 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.0 release notes for specific changes and security fixes in this release.

New in SeaMonkey 2.53.10.1 (Dec 14, 2021)

  • For SeaMonkey 2.53.10.1, the following extensions are included:
  • ChatZilla
  • DOM Inspector
  • Lightning
  • Beta versions also contain the following extension:
  • SeaMonkey Debug and QA UI
  • What's New in SeaMonkey 2.53.10.1:
  • SeaMonkey 2.53.10.1 contains (among other changes) the following major changes relative to SeaMonkey 2.53.10:
  • Security fix for NSS code bug 1737470.
  • Only use networks and servers in lower case in ChatZilla bug 1742502.
  • Change classic form icon in SeaMonkey composer bug 1710915.
  • Addition fixes for SeaMonkey 32x32 default icons on Windows and macOS bug 1729153.
  • SeaMonkey 2.53.10.1 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When History is invoked, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.10.1 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • Additional important security fixes up to Current Firefox 91.4 ESR and a few enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SeaMonkey 2.53.10.1 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.0 release notes for specific changes and security fixes in this release.
  • SeaMonkey-specific changes:
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug and link it to bug 1367257. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.
  • Extensions (Add-ons) and Themes:
  • Extensions and Themes for SeaMonkey 2.53.10.1 can be installed from the SeaMonkey Add-Ons website or the "Get Add-Ons" section in the Add-ons Manager.
  • Extensions with binary components such as Enigmail only work for the specific platform they are released (e.g. win extension for Windows, linux64 for Linux 64 bits). Besides, matching version of extensions for SeaMonkey may not be the latest available of those versions. Therefore, they need to be adjusted for each new SeaMonkey release, which also means that an old version of such an add-on can break SeaMonkey if you disabled compatibility checking (which e.g. happens when you install the Add-on Compatibility Reporter add-on). Please, note the following warnings and advice regarding extensions:
  • Previous versions supported a proprietary JavaScript try/catch solution. This was removed in bug 1228841 and needed to be backported to 2.53.10b1. The backport might break some add-ons. One add-on affected is the classic version of DownThemAll. A fixed version is available from the DTA forked repo.
  • For Enigmail, please refer to the Enigmail page.
  • The latest supported version is 2.0.9 Enigmail but there have been some problems reported against it.
  • Adblock Plus 2.9.1 may cause huge memory and CPU consumption and is not recommended or officially supported in this SeaMonkey version. Consider switching to uBlock.
  • Lightbird 0.7.1. is not compatible with this version. The message preview pane will not update itself correctly.
  • The latest 1.16.x working version of uBlock can be found here. Please install the latest legacy version.
  • The latest working version of NoScript Classic 5.x can be found here.
  • Dictionaries in WebExtension formats do not work, even though they appear to install correctly. Support for them will be added at a later date. Please install the latest classic version from the dictionary history or unpack the dictionary inside the WebExtension package into your /dictionaries directory.
  • Lightweight themes are no longer provided on the SeaMonkey Add-ons site.
  • Full theme add-ons may need changes because of user interface and internal changes. If you find any problem with themes, contact the theme author. Before reporting a problem with the user interface please make sure to recreate it with either the Classic or Modern theme.
  • Because of security backports which removed obsolete code, Session Manager add-on version 0.8.1.14 or above is required to be compatible with current and future 2.53 releases.

New in SeaMonkey 2.53.10 (Nov 16, 2021)

  • SeaMonkey 2.53.10 contains (among other changes) the following major changes relative to SeaMonkey 2.53.9.1:
  • Minor fixes for testdisplay command in ChatZilla bug 1727976.
  • Show CTCP requests (excluding ACTION and DCC) bug 1722156.
  • IRCv3: Add support for server-time bug 1724586.
  • Add localization note for network editor dialog width in ChatZilla bug 1727977.
  • IRCv3: Add support for extended-join and account-notify bug 1722159.
  • Add ability to collapse message groups in ChatZilla bug 1724588.
  • Fix JS strict warnings in unescapeTagValue in ChatZilla bug 1727989.
  • IRCv3: Add support for invite-notify bug 1722161.
  • IRCv3: Add support for batch bug 1724589.
  • Fix JS strict warning in addHistory in cZ static.js bug 1727992.
  • IRCv3: Add support for cap-notify bug 1722162.
  • Stop using canonical name as collection keys in ChatZilla bug 1728025.
  • IRCv3: Add support for TLS and STS bug 1722166.
  • Helper function for renaming irc server properties in ChatZilla bug 1728027.
  • IRCv3: Add support for MONITOR bug 1722174.
  • Remove use of msg.commasp in ChatZilla bug 1726965.
  • Allow shiftKey to modify behaviour of link clicking in cZ bug 1713458.
  • IRCv3: Add support for echo-message bug 1722211.
  • In ChatZilla make /commands return all matches starting with pattern bug 1726966.
  • Use SeaMonkey prefs to determine how links behave in cZ bug 1713467.
  • Allow parameters to be localised in ChatZilla bug 1724105.
  • Add identify command to cZ and hook into password management bug 1713470.
  • IRCv3.1: Implement SASL with PLAIN mechanism bug 1717545.
  • IRCv3: Add support for message tags bug 1724584.
  • Add last read message divider to ChatZilla bug 1729159.
  • IRCv3: Add support for account-tag bug 1724585.
  • Missing option "text encoding Unicode/UTF-8" in preferences - Mailnews bug 1679260.
  • Detect Crashreporter using AppConstants in SeaMonkey bug 1735236.
  • Link about LEGACY extensions in Add-ons Manager is broken bug 1656797.
  • Update help for clear private data preferences and dialog bug 1728911.
  • Fix typo in cs_nav_prefs_appearance bug 1737473.
  • Drop leftover "Edit Menu" comment from messageWindow.xul and addressbook.xul bug 1725121.
  • Add dummy tab routines to SeaMonkey mailnews tab browser bug 1735243.
  • Folder pane and tab/window title not updated correctly when opening in new tab bug 1726940.
  • Allow mail tab bar to be controlled separately to browser tab bar bug 1724515.
  • Copy any user set values for new mail.tabs prefs bug 1729165.
  • Merge Master Passwords and Passwords pref panes into a single pref pane bug 1728099.
  • Move warning about redirection pref from Content to Privacy & Security pane bug 1728185.
  • Move website icons prefs from content pref pane to browser pref pane bug 1727425.
  • Move browser / mailnews system integration prefs into advanced pane bug 1727659.
  • Have separate opentabfor.middleclick for mailnews bug 1727948.
  • Add removeBrowser helper for tabbrowser bug 1730391.
  • Put in a so it's easy to overlay bug 1730392.
  • Allow browser focus to be avoided bug 1720003.
  • SeaMonkey 32x32 default icon has light stripe at the bottom bug 1729153.
  • Support and in SeaMonkey bug 1730408.
  • Middleclick on browser tab handled twice (closes tab and loads URL from primary or clipboard) bug 1734407.
  • Unable to create a new "Saved Search Folder" using "Save View as a Folder..." bug 1738669.
  • The following bugs were fixed in our branch of the Gecko source code only:
  • Enable compression for standard http connections bug 1728996.
  • Support VS2022 for compiling under Windows bug 1728988.
  • SeaMonkey 2.53.10 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When invoking History, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.10 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.10 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.0 release notes for specific changes and security fixes in this release.
  • Additional important security fixes up to Current Firefox 78.15 ESR and a few enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SeaMonkey-specific changes:
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug and link it to bug 1367257. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.
  • Extensions (Add-ons) and Themes:
  • Extensions and Themes for SeaMonkey 2.53.10 can be installed from the SeaMonkey Add-Ons website or the "Get Add-Ons" section in the Add-ons Manager.
  • Extensions with binary components such as Enigmail only work for the specific platform they are released (e.g. win extension for Windows, linux64 for Linux 64 bits). Besides, matching version of extensions for SeaMonkey may not be the latest available of those versions. Therefore, they need to be adjusted for each new SeaMonkey release, which also means that an old version of such an add-on can break SeaMonkey if you disabled compatibility checking (which e.g. happens when you install the Add-on Compatibility Reporter add-on). Please, note the following warnings and advice regarding extensions:
  • Previous versions supported a proprietary JavaScript try/catch solution. This was removed in bug 1228841 and needed to be backported to 2.53.10b1. The backport might break some add-ons. One add-on affected is the classic version of DownloadThemAll. Please ask in the support groups if a new version is already available.
  • For Enigmail, please refer to the Enigmail page.
  • The latest supported version is 2.0.9 Enigmail but there have been some problems reported against it.
  • Adblock Plus 2.9.1 may cause huge memory and CPU consumption and is not recommended or officially supported in this SeaMonkey version. Consider switching to uBlock.
  • Lightbird 0.7.1. is not compatible with this version. The message preview pane will not update itself correctly.
  • The latest 1.16.x working version of uBlock can be found here. Please install the latest legacy version.
  • The latest working version of NoScript Classic 5.x can be found here.
  • Dictionaries in WebExtension formats do not work, even though they appear to install correctly. Support for them will be added at a later date. Please install the latest classic version from the dictionary history or unpack the dictionary inside the WebExtension package into your /dictionaries directory.
  • Lightweight themes are no longer provided on the SeaMonkey Add-ons site.
  • Full theme add-ons may need changes because of user interface and internal changes. If you find any problem with themes, contact the theme author. Before reporting a problem with the user interface please make sure to recreate it with either the Classic or Modern theme.
  • Because of security backports which removed obsolete code, Session Manager add-on version 0.8.1.14 or above is required to be compatible with current and future 2.53 releases.
  • Known Issues:
  • This list covers some of the known problems with SeaMonkey 2.53.10. Please read this before reporting any new bugs.
  • Some translations are missing in a few languages in the user interface and are being substituted with the corresponding US English terms. We plan to update the l10n translations for the final version but some languages like Polish are now missing a translator. Consider helping out with translations if you would like to have a 100% translated version.
  • Opening single new tabs from the Library always loads them in the foreground. The problem is tracked in bug 1619108
  • SeaMonkey will not start under Linux if you downloaded the wrong package.
  • We are providing x86 and x64 versions of SeaMonkey for Linux. For newer distributions you probably need the Linux x64 version.
  • Lightning or one of the distributed extensions is disabled under Add-ons.
  • Starting with SeaMonkey 2.53.7b1 the distributed extensions can no longer be removed. If you have previously enabled one then under some circumstance it might be disabled during the upgrade process. If the extension is disabled and can not be enabled then it is because an old or incompatible version is still present in your profile.
  • To clean out old versions use the following instructions:
  • Enter "about:config" in the location bar.
  • Enter "extensions.installedDistroAddon" in the search field.
  • Reset (delete) all keys found.
  • Open the Add-ons Manager. If the "remove" button is shown for the disabled extension use it. Stored data like your personal calendars will not be removed by this action.
  • Restart SeaMonkey.
  • Disable any distributed extension you do not wish to use.
  • Unable to connect to secure sites and a certificate error is shown.
  • In 99% of all cases this issue is caused by the same problem. Your antivirus software or custom firewall acts as a man in the middle and intercepts secure https traffic. In order to intercept and scan this encrypted network traffic, it normally uses a vendor specific certificate which is not installed by default in SeaMonkey by the third party software installer. If you want to keep this feature working you need to install one or more certificate(s) from the antivirus software in SeaMonkey. You need to ask your antivirus software vendor where they are located. Consult the SeaMonkey online help to find out how you can import and manage certificates.
  • If you experience a hang and/or get a message box warning that a script is busy when opening the Data Manager try deleting the webappsstore.* files from your profile folder when SeaMonkey is not running. These files contain data stored by websites and will be recreated during the next start. If you are unsure if the information is needed please back up the files before deleting them. The problem is tracked in bug 1305624 but so far no coding error has been found. This problem has been reported frequently when trying to manage passwords. But the problem will generally happen just after you open the Data Manager, because this component is also used for managing cookies, site preferences permissions and other settings.
  • If you are running Windows 7 "Send to > Mail recipient" might not work. More information can be found in bug 1356902. As a workaround install the "Microsoft Visual Studio 2015 to 2019" redistributable runtime library. For x86 install the VS2019 x86 runtime.
  • If you are using the x64 build install the VS2019 x64 runtime. SeaMonkey was built using the latest VS2019 compiler so make sure to upgrade any older VS2017 runtime.
  • If you experience a delay showing the first page after start, please delete the Safebrowsing folder in your profile. Bad Safebrowsing data may delay showing the first page for up to 30 seconds. The problem is tracked in bug 1432274. This can occur even if you are not using Safebrowsing because the lists are always fetched.
  • SeaMonkey does not currently support the WebExtensions add-on api. Some popular add-ons like NoScript and uBlock Origin are no longer shown because of this on the SeaMonkey add-ons website. You can usually get compatible versions from the manufacturers site. WebExtensions support is a planned feature for 2.57. For dictionaries please install the latest non webext version.
  • The SSL 3.0 encryption protocol is no longer supported due to security concerns (bug 1106470). Legacy websites may still rely on it and will not work with the newer TLS 1.x protocols. Contact the website administrator to update their server to resolve the issue at the source.
  • The Remember Passwords add-on breaks password handling. Please disable or uninstall this add-on using the Add-ons Manager.
  • You cannot set up a new Sync account or pair a device anymore (bug 998807).
  • Data loss warning: If you use a profile with this or any later version and then try to go back to SeaMonkey 2.49.5 or earlier, SeaMonkey will rename your bookmarks and history file to places.sqlite.corrupt and create a new places.sqlite file, effectively resetting your browsing history. This is because the internal format changed and the upgrade process only works in one direction. Additionally, running MailNews with local folders and POP3 mail filters may produce summary files that are not correctly read by previous versions of SeaMonkey. If you decide to go back to a previous version of SeaMonkey, you should do it from a profile backup only. Stored passwords and local storage will also be unavailable in the old version.
  • After creating a news account through clicking a news URL, the MailNews account wizard may be broken (the account type will always be News). To work around the problem, set the mail.server.serverX.valid pref (where X is the internal number of the corresponding news account) to true in about:config, or delete the invalid news account (bug 521861).
  • WebRTC has been disabled by default. It needs an add-on to enable it per site. See the webrtc-permissions-ui-toggle add-on.
  • Web pages may appear differently in the MailNews feed reader than in the browser (bug 662907). Workaround: Add a "noscript {display:none}" rule to your userContent.css (note that the Stylish add-on cannot be used here since it does not integrate with the MailNews feed reader).
  • Lightning keyboard shortcuts for accessing the calendar tab from within the MailNews window or from the main menu (Ctrl+Shift+C/D) do not work. (bug 514512).
  • If you try to start SeaMonkey using a locked profile, it will crash (see bug 573369).
  • In ChatZilla users are unable to add an exception for an invalid certificate unless an override is added to the preferences (see bug 1738597).
  • Linux:
  • SeaMonkey 2.53.7b1 can not be automatically updated to later beta versions as it is set to the wrong update channel. To overcome this, make sure SeaMonkey 2.53.7b1 is not running, edit the channel-prefs.js file located in the defaults/pref directory of the installation directory for SeaMonkey 2.53.7b1 and change the app.update.channel pref from "release" to "beta". When SeaMonkey is restarted it should then find future beta releases.

New in SeaMonkey 2.53.10 Beta 1 (Oct 29, 2021)

  • Minor fixes for testdisplay command in ChatZilla bug 1727976.
  • Show CTCP requests (excluding ACTION and DCC) bug 1722156.
  • IRCv3: Add support for server-time bug 1724586.
  • Add localization note for network editor dialog width in ChatZilla bug 1727977.
  • IRCv3: Add support for extended-join and account-notify bug 1722159.
  • Add ability to collapse message groups in ChatZilla bug 1724588.
  • Fix JS strict warnings in unescapeTagValue in ChatZilla bug 1727989.
  • IRCv3: Add support for invite-notify bug 1722161.
  • IRCv3: Add support for batch bug 1724589.
  • Fix JS strict warning in addHistory in cZ static.js bug 1727992.
  • IRCv3: Add support for cap-notify bug 1722162.
  • Stop using canonical name as collection keys in ChatZilla bug 1728025.
  • IRCv3: Add support for TLS and STS bug 1722166.
  • helper function for renaming irc server properties in ChatZilla bug 1728027.
  • IRCv3: Add support for MONITOR bug 1722174.
  • Remove use of msg.commasp in ChatZilla bug 1726965.
  • Allow shiftKey to modify behaviour of link clicking in cZ bug 1713458.
  • IRCv3: Add support for echo-message bug 1722211.
  • In ChatZilla make /commands return all matches starting with pattern bug 1726966.
  • Use SeaMonkey prefs to determine how links behave in cZ bug 1713467.
  • Allow parameters to be localised in ChatZilla bug 1724105.
  • Add identify command to cZ and hook into password management bug 1713470.
  • IRCv3.1: Implement SASL with PLAIN mechanism bug 1717545.
  • IRCv3: Add support for message tags bug 1724584.
  • Add last read message divider to ChatZilla bug 1729159.
  • IRCv3: Add support for account-tag bug 1724585.
  • Missing option "text encoding Unicode/UTF-8" in preferences - Mailnews bug 1679260.
  • Detect Crashreporter using AppConstants in SeaMonkey bug 1735236.
  • Link about LEGACY extensions in Add-ons Manager is broken bug 1656797.
  • Update help for clear private data preferences and dialog bug 1728911.
  • Fix typo in cs_nav_prefs_appearance bug 1737473.
  • Drop leftover "Edit Menu" comment from messageWindow.xul and addressbook.xul bug 1725121.
  • Add dummy tab routines to SeaMonkey mailnews tab browser bug 1735243.
  • Folder pane and tab/window title not updated correctly when opening in new tab bug 1726940.
  • Allow mail tab bar to be controlled separately to browser tab bar bug 1724515.
  • Copy any user set values for new mail.tabs prefs bug 1729165.
  • Merge Master Passwords and Passwords pref panes into a single pref pane bug 1728099.
  • Move warning about redirection pref from Content to Privacy & Security pane bug 1728185.
  • Move website icons prefs from content pref pane to browser pref pane bug 1727425.
  • Move browser / mailnews system integration prefs into advanced pane bug 1727659.
  • Have separate opentabfor.middleclick for mailnews bug 1727948.
  • Add removeBrowser helper for tabbrowser bug 1730391.
  • Put in a so it's easy to overlay bug 1730392.
  • Allow browser focus to be avoided bug 1720003.
  • Seamonkey 32x32 default icon has light stripe at the bottom bug 1729153.
  • Support and in SeaMonkey bug 1730408.
  • middleclick on browser tab handled twice (closes tab and loads URL from primary or clipboard) bug 1734407.
  • SeaMonkey 2.53.10 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When invoking History, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".

New in SeaMonkey 2.53.9.1 (Sep 28, 2021)

  • SeaMonkey 2.53.9.1 contains (among other changes) the following major changes relative to SeaMonkey 2.53.9:
  • Fix the lazy loading of images from some websites bug 1727967.
  • Move certain font family defaults from serif to sans serif bug 1727982.
  • SeaMonkey 2.53.9.1 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When invoking History, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • SeaMonkey 2.53.9.1 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes.
  • SeaMonkey 2.53.9.1 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.0 release notes for specific changes and security fixes in this release.
  • Additional important security fixes up to Current Firefox 78.14 ESR and a few enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.
  • SeaMonkey-specific changes:
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug and link it to bug 1367257. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.

New in SeaMonkey 2.53.9 (Aug 27, 2021)

  • There is now an option to clear browser history during shutdown bug 1621445.
  • Uninstall plugin command for ChatZilla bug 541719.
  • Update icons used in ChatZilla status bar bug 1710238 and bug 1710249.
  • Make ChatZilla understand mIRC color code 99 bug 1710298.
  • Implement IRCv3 basic CAP negotiation bug 1717539 and CAP LIST and update CAP ACK and CAP LS bug 1710313.
  • Use Unicode instead of images for emojis in ChatZilla bug 1711375 and add some extra emojis bug 1711376.
  • Use SeaMonkey's configured web search rather than a separate one in ChatZilla bug 1712498.
  • Add a networks editor to ChatZilla bug 1716232.
  • Implement IRCv3 away-notify bug 1717543, chghost and userhost-in-names bug 1717544, self-messaging bug 1722212 and WHOX bug 1722214.
  • Link to SeaMonkey website in debugQA for verification sites and development section bug 1685606.
  • Send button should be disable until we have a recipient bug 104973.
  • Remove need to use a modifier for marking messages as unread bug 1719216.

New in SeaMonkey 2.53.9 Beta 1 (Aug 11, 2021)

  • For SeaMonkey 2.53.9, the following extensions are included:
  • ChatZilla
  • DOM Inspector
  • Lightning
  • Beta versions also contain the following extension:
  • SeaMonkey Debug and QA UI
  • CHANGES:
  • There is now an option to clear browser history during shutdown bug 1621445.
  • Uninstall plugin command for ChatZilla bug 541719.
  • Update icons used in ChatZilla status bar bug 1710238 and bug 1710249.
  • Make ChatZilla understand mIRC color code 99 bug 1710298.
  • Implement IRCv3 basic CAP negotiation bug 1717539 and CAP LIST and update CAP ACK and CAP LS bug 1710313.
  • Use Unicode instead of images for emojis in ChatZilla bug 1711375 and add some extra emojis bug 1711376.
  • Use SeaMonkey's configured web search rather than a separate one in ChatZilla bug 1712498.
  • Add a networks editor to ChatZilla bug 1716232.
  • Implement IRCv3 away-notify bug 1717543, chghost and userhost-in-names bug 1717544, self-messaging bug 1722212 and WHOX bug 1722214.
  • Link to SeaMonkey website in debugQA for verification sites and development section bug 1685606.
  • Send button should be disable until we have a recipient bug 104973.
  • Remove need to use a modifier for marking messages as unread bug 1719216.
  • SeaMonkey 2.53.9 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When invoking History, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".

New in SeaMonkey 2.53.8.1 (Jul 22, 2021)

  • Archive message action does not work bug 1718839.
  • Do not preserve offlineMsgSize parameter when moving/copying emails between folders bug 1720202 and bug 1430480.
  • Move thread code to threadPane.js and remove messengerdnd.js bug 515675.

New in SeaMonkey 2.53.8 (Jun 30, 2021)

  • Serious performance improvements and bug fixes tracked in bug 1633339 and bug 1711050.
  • Language attributes with country codes not recognized when building the Website Navigation Bar link toolbar bug 134436 and bug 1709443.
  • Optimize SeaMonkey icons for speed and optional higher quality for branding bug 1362210 and bug 1699322.
  • Support from= option when opening email compose window from the command line bug 1628671.
  • Update subject handling and GenericSendMessage function in compose window bug 1693994.
  • All message windows should update when view preferences are changed bug 1694765.
  • Improve marking of multiple messages as read / unread bug 1700530.
  • Show version numbers again in the add-on manager by the partial backout of bug 1161183.
  • Update available networks in chatZilla (including adding libera.chat)bug 1704392 and bug 1712505.
  • Change default port for IRC via TLS/SSL to 6697 bug 1704280.
  • Remove chatZilla and Lightning extension language packs and incorpate localisations within the main language pack bug 1604663.
  • Fix address drag and drop handling in compose window bug 1712002 and bug 1712227.
  • Further fixes for legacy generators and the deprecated for each statement in add-ons and the Add-on SDK bug 1702903.
  • For developers, fork DOMi repo into main SeaMonkey one which means no need to separately checkout the extension bug 1700003.

New in SeaMonkey 2.53.7.1 (Apr 16, 2021)

  • Fix for legacy generators and the deprecated for each statement in add-ons and the Add-on SDK bug 1702903.
  • Fix for handling of dead keys in text input fields in GTK 3.24.26+ bug 1701288.

New in SeaMonkey 2.53.7 (Mar 30, 2021)

  • Remove Flash and NPAPI support bug 1688415.
  • Switch packaged extensions to be global bug 1659298.
  • Add Insert Forms to Composer bug 1684611.
  • Fix an issue with copying to IMAP sent folder and some reference count leaks in mailnews bug 1689890.
  • Tailing to delay tracker requests and enhance performance has been enabled bug 1358060.
  • Fix an issue with favorite and recent folders not showing in macOS bug 1695869.
  • Various security and general platform fixes.
  • The ChatZilla source has been integrated into SeaMonkey and no longer needs to be checked out separately if you build your own release bug 1551033.

New in SeaMonkey 2.53.6 (Jan 24, 2021)

  • Improve usability of multiple mailboxes/folders selectionbug 1600103.
  • Add Greek localisation (el).
  • Remove more RDF from mailnews code.
  • Switch to mozilla as topsrcdir and component for building is comm/suite now.
  • Rust support is now up to 1.48 and official build is now using 1.47.0
  • Various security and general platform fixes.

New in SeaMonkey 2.53.5.1 (Nov 21, 2020)

  • Fix advertising of av1 support bug 1490877.
  • Fix some issues found with supporting new macOS.
  • Various security and general platform fixes.

New in SeaMonkey 2.53.5 (Nov 14, 2020)

  • Provide WebP support bug 1653869.
  • Add startpage.com as a search engine available to all locales bug 1655283.
  • Added av1 support.
  • Included latest version of freetype2.
  • Added support for the resizeObserver web API.
  • Support for rust 1.47.0 on Linux and macOS platforms.
  • Dropped support for use of system sqlite.
  • Various security and general platform fixes.

New in SeaMonkey 2.53.4 (Sep 22, 2020)

  • SeaMonkey 2.53.4 contains (among other changes) the following major changes relative to SeaMonkey 2.53.3:
  • Upgraded NSS to 3.53.1 bug 1643859.
  • Updated to Unicode 11 for SpiderMonkey bug 1466471.
  • Updated bundled Twemoji Mozilla font to v0.5.1 to support newer emojis bug 1644346.
  • Updated how photos are handled in the addressbook bug 1641705.
  • Removed outdated RSS feed handlers bug 1643716.
  • Fix initialisation of TodayPane mini-day, to show the right day bug 1479628.
  • Fixed sizing issue of HTML mail question (askSendFormat) dialog bug 1583415.
  • Update of help page content and links.
  • Various security and general platform fixes.
  • SeaMonkey 2.53.4 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When invoking History, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • The layout panel was added to the CSS Grid tools.
  • TLS 1.3 is the default SSL version now.
  • The only NPAPI plugin which will work with SeaMonkey 2.53.4 is Flash. Support for other NPAPI plugins like Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
  • SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
  • Other:
  • SeaMonkey 2.53.4 uses the same backend as Firefox and contains the relevant Firefox 60.6 security fixes.
  • SeaMonkey 2.53.4 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.0 release notes for specific changes and security fixes in this release.
  • Additional important security fixes up to Current Firefox 78.1 ESR and a few enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.

New in SeaMonkey 2.53.4 Beta 1 (Aug 20, 2020)

  • Upgraded NSS to 3.53.1 bug 1643859.
  • Updated to Unicode 11 for SpiderMonkey bug 1466471.
  • Updated bundled Twemoji Mozilla font to v0.5.1 to support newer emojis bug 1644346.
  • Updated how photos are handled in the addressbook bug 1641705.
  • Removed outdated RSS feed handlers bug 1643716.
  • Fixed sizing issue of HTML mail question dialog.
  • Update of help page content and links.
  • Various security and general platform fixes.

New in SeaMonkey 2.53.3 (Aug 20, 2020)

  • The LaTex tool TexZilla, used for inserting Math, has been upgraded to 1.0.2.
  • It is now possible to customize the toolbars in Composer and the formatting toolbar in Mailnews composition.
  • All folders of an account can now be marked as read.
  • There is now an option for not advertizing SeaMonkey at all in the user agent.
  • The preference for hiding the toolbar and menubar grippies can now be changed from "Preferences->Appearance".
  • The tab bar is now shown by default when only one tab is open bug 1634879. This change was needed as new users did not see either the tab bar or its "Open a new tab" button on a fresh installation. Existing users of the option "Hide the tab bar when only one tab is open" will need to make a one time only change in "Preferences->Browser->Tabbed Browsing" if they want to go back to the old setting.
  • Update of help page content and links.
  • SeaMonkey language packs are now version specific and will be disabled as part of the profile upgrade following the installation of a later version.
  • Search Engines have been centralized and updated in bug 1300198.
  • Address book now has updated IM fields, improved layout for card view pane, improved multi-word search, ability to search across multiple address books, more granular prompts when deleting items, print on the context menus and print button on the toolbar.
  • Multimedia support has been updated in preparation of supporting more audio video formats in the next releases. For enhanced security the Rust multimedia parser is now used for this and the libstagefright package has been removed.

New in SeaMonkey 2.53.1 Beta 1 (Jan 20, 2020)

  • The Bookmarks Manager has switched its name to Library, and now also includes the History list. When invoking History, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
  • Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
  • Added Layout panel to CSS Grid tools.
  • TLS 1.3 is the default version now.

New in SeaMonkey 2.49.5 (Sep 5, 2019)

  • Based on Mozilla Firefox 52.9 ESR and further enhanced, it delivers those same developments in web technologies such as HTML5, hardware acceleration and improved JavaScript speed.

New in SeaMonkey 2.49.2 (Feb 19, 2018)

  • You were unable to add or edit properties for images and links in the 2.49.1 Composer. The problem, tracked in bug 1417819, has been fixed. We are sorry for the inconvenience it caused.
  • SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug and link it to Switch Linux builds to GTK3 with SeaMonkey 2.49. Pleae try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.
  • With some Linux themes, the menulist- and history-dropmarker didn't show. It was actually there but only 1 pixel wide. The problem, tracked in bug 1331208, has been fixed. As a result the dropmarker in the location bar is now also shown a little wider under Windows.
  • Scrollbars didn't show the buttons under Linux. The problem, tracked in bug 1269145, has been fixed. We will try to improve the visual experience in a follow-up version.
  • WebRTC has been disabled by default. It needs an add-on to enable it per site. See the webrtc-permissions-ui-toggle add-on.
  • The active title bar was not visually emphasized under Linux or using the Windows XP/Vista/7 Classic theme. We opted to show it with a striped color bar in bug 1398973.
  • For security, parts of bug 1035091 were ported in bug 1411708. This might cause problems with add-ons like Stylish which use moz-document. Set the pref "layout.css.moz-document.content.enabled" to "true" to overcome this but be aware that this disables the added security fix.

New in SeaMonkey 2.48 (Jul 21, 2017)

  • The bug which prevented you to set the default search engine in SeaMonkey 2.46 has been fixed. If you see any problems with this please report it in bug 1265881.
  • The Errror Console is now a part of SeaMonkey. It was replaced by the Developer Tools Web and Browser Console in Firefox which both are also available in SeaMonkey. If you use css to style the console please note that it is now located in "chrome://communicator/content/console/console.xul/".
  • The Help Viewer is now a part of SeaMonkey and has been deleted from Mozilla Gecko.
  • SeaMonkey now uses the HTTP cache v2. For technical details please check bug 1241622.
  • Troubleshooting Information in "about:support" is displayed in a better readable layout.

New in SeaMonkey 2.48 Beta 1 (Apr 18, 2017)

  • The bug which prevented you to set the default search engine in SeaMonkey 2.46 has been fixed. If you see any problems with this please report it in bug 1265881.
  • The Errror Console is now a part of SeaMonkey. It was replaced by the Developer Tools Web and Browser Console in Firefox which both are also available in SeaMonkey. If you use css to style the console please note that it is now located in "chrome://communicator/content/console/console.xul/".
  • The Help Viewer is now a part of SeaMonkey and has been deleted from Mozilla Gecko.
  • SeaMonkey now uses the HTTP cache v2. For technical details please check bug 1241622.
  • Troubleshooting Information in "about:support" is displayed in a better readable layout.

New in SeaMonkey 2.33 (Mar 11, 2015)

  • Security notification bars now feature tracking controls.
  • The tracking/privacy preferences pane has been updated.

New in SeaMonkey 2.32 (Jan 14, 2015)

  • The Spell Check dialog is now resizable.
  • Generational Garbage Collection has been enabled.
  • Improved handling of dynamic styling changes to increase responsiveness.
  • Implemented HTTP Public Key Pinning Extension (for enhanced authentication of encrypted connections).
  • Reduced resource usage for scaled images.
  • Fixed several stability issues.

New in SeaMonkey 2.30 (Oct 16, 2014)

  • OMTC (Off Main Thread Compositing) has been enabled by default on Windows.
  • OpenH264 support (sandboxed) has been added.
  • A new CSP (Content Security Policy) backend was implemented.
  • Support for connecting to HTTP proxies over HTTPS was implemented.
  • Improved reliability of the session restoration.
  • WebCrypto support has been enhanced: Added RSA-OAEP, PBKDF2 and AES-KW support, implemented wrapKey and unwrapKey, enabled import/export of JWK-formatted keys.
  • Fixed several stability issues.

New in SeaMonkey 2.29 (Sep 8, 2014)

  • URLs that are too long to be shown completely appear in a tooltip now when hovering the location bar.
  • Coloring of the location bar for HTTPS URLs can be disabled through Preferences now.
  • Certain search engines can be discovered automatically now.
  • The status bar padlock icon features a context menu now.
  • You can now insert formulas in Composer using a dialog (LaTeX to MathML).
  • Feed items can be tagged automatically according to feed category tags now.
  • Searching within a message compose window will now display the find toolbar.
  • The account name is now shown in the status bar when downloading messages from POP servers.
  • Localizability of custom reply headers has been improved (mailnews.reply_header_* preferences).
  • Contact autocompletion in message composition windows now searches for all terms separately (AND search).
  • You can now search for contacts containing parentheses.

New in SeaMonkey 2.26 (May 2, 2014)

  • The delimiter for forwarded messages can now be configured.
  • An option to not strip signatures on reply has been added to prevent top signatures from deleting the body.

New in SeaMonkey 2.25 (Mar 20, 2014)

  • Newsgroup names can now be entered using autocompletion.
  • See the changes page for a more complete overview.

New in SeaMonkey 2.24 (Feb 6, 2014)

  • The DoNotTrack and Prompt on Sanitize preferences are now kept in sync.
  • A pref (mailnews.p7m_external) has been added to allow users to choose an alternate application/pkcs7-mime handling.
  • Support for Atom Threading Extensions (RFC 4685) has been added.
  • Migrating profiles from Thunderbird supports the new signons file format now (support for the old format has been dropped).
  • Autocomplete drop-downs (e.g. used on the Location Bar and Open Location dialog) now show favicons for their entries.
  • The account name is now displayed in the status bar for all messages when checking mail.
  • IMAP alert messages now show the server of the corresponding mail account.
  • Newsgroup names are now searched for all search strings combined (AND-search) on the subscribe dialog.

New in SeaMonkey 2.23 (Dec 12, 2013)

  • Download progress is now shown in the Mac OS X app dock icon.
  • EXIF orientation is now being used when displaying attached images in MailNews.
  • "This folder is being processed... to get messages." alerts on active MailNews folders now identify the account or folder.
  • MailNews notifications have a new look.

New in SeaMonkey 2.22 (Nov 18, 2013)

  • Sorting messages by date can now be configured to look at the thread root instead of the newest message in it (pref: mailnews.sort_threads_by_root).
  • Plugins doorhangers now allow to activate different plugin types independently.
  • The proxy popup is now also available from the MailNews main window.
  • A new Recipients column has been added that shows all recipients (To, CC, BCC).
  • The default HTML5 audio/video player controls allow to change the playback rate now.
  • A "Validate this page" entry has been added to Tools/Web Development.
  • The Firefox devtools debugger can now be used to debug SeaMonkey remotely.

New in SeaMonkey 2.21 (Sep 18, 2013)

  • Implemented an option to thread messages received by date.
  • Allowed deletion of news posts by default.
  • Implemented optional taskbar preview-per-tab.
  • Added support (permission prompt) for desktop notifications.
  • Added Isn't operator for searching by Priority.

New in SeaMonkey 2.20 Beta 3 (Jul 31, 2013)

  • Some private windows appeared in the undo close window list (bug 887045).
  • The Private Browsing shortcut key has been changed as it conflicted with spellcheck (bug 891081).
  • Remote debugging did not work if any tabs had no title (bug 889352).
  • Clicking on new mail notifcation opened two MailNews windows when no MailNews window was open (bug 840474).

New in SeaMonkey 2.19 (Jul 3, 2013)

  • SeaMonkey-specific changes:
  • Mark -> As Read now checks the state of all selected messages instead of only the first one's.
  • Notifications for mixed content blocker have been implemented.
  • A new 3rd-party cookie restriction to visited websites option has been added to the Cookies pref pane.
  • The context menu Search option is now available for textareas and input fields.
  • Website storage mechanisms are now available in the Data Manager (localStorage, indexedDB, etc.).
  • "Open Containing Folder" is now already available during download.
  • See the changes page for minor changes.
  • Mozilla platform changes:
  • asm.js optimizations (OdinMonkey) have been enabled for major performance improvements.
  • Improved WebGL rendering performance through asynchronous canvas updates.
  • Plain text files displayed within the browser will now word-wrap.
  • For user security, the Components object is no longer accessible from web content.
  • Improved memory usage and display time when rendering images.
  • The Pointer Lock API can now be used outside of fullscreen.
  • CSS3 Flexbox has been implemented and enabled by default.
  • The new Web Notifications API has been implemented.
  • Added clipboardData API for JavaScript access to a user's clipboard.
  • Support for new HTML5 and elements has been added.
  • Fixed several stability issues.

New in SeaMonkey 2.19 Beta 2 (Jun 27, 2013)

  • Mitigate clickjacking of about:certerror (bug 871536).
  • Workaround for unusually large DirectWrite font line heights (bug 868495).
  • Private downloads should ignore the Download Manager (bug 873355).
  • Private windows should not opt out of the private browsing session (bug 874042).
  • Private sidebar searches should not open in a normal window (bug 875889).
  • Last page visited should not include private browsing windows (bug 883577).

New in SeaMonkey 2.19 Beta 1 (Jun 24, 2013)

  • The new mail alert has been disabled for now due to issues on Mac (Bug 840474).
  • The Geolocation prompt does not offer an action in Private Browsing mode anymore if the action remembers permission for more than a session (Bug 870728).
  • A slightly less useless access key has been chosen for the new Error Console Filter textbox label (Bug 860851).
  • Mixed content blocker preferences are now handled by Sync (Bug 860970).
  • LDAP passwords were requested for each lookup even if they were saved (Bug 833971).
  • Get New Messages for All Accounts has been fixed (Bug 855631).
  • The "File" button in the "Search messages" window has been renamed to "Move" (Bug 325777).
  • The entries in the "Trust junk mail headers set by" menu list are now sorted (Bug 847172).
  • The check for the allowed mail storage directory has been made more universal and accessible to extensions (Bug 848477).
  • A wrong message and reason was reported with untrusted CA roots when signing email (Bug 465351).
  • The IMAP-specific "Empty trash" confirmation dialog has been removed and the mailnews.*.dontAskAgain and mail.*.dontAskAgain prefs been merged (Bug 448624).
  • Help now explains what happens when Safe Browsing blocks a website (Bug 852809).
  • Email addresses with trailing whitespace could be displayed wrongly when composing and cause lost mails and malformed duplicate address book entries (Bug 286760).
  • Switching the account during message composing did not apply the signing prefs from the new account (Bug 624432).
  • The Help Glossary has been extended with new Privacy & Security terms (Bug 847182).
  • Growl support has been removed again (Bug 852461).
  • Safe Browsing debug has been turned off and Sync support turned on (Bug 851789).
  • The Bookmarks Toolbar was not populated with items if the grippy was collapsed when the browser window was opened (Bug 818437).
  • Special mail folder icons were not shown for IMAP shared folders (bug 840003).
  • Null bytes are now stripped from document titles when setting the window title in order to prevent Private Browsing spoofing (Bug 851527).
  • Invalid message ContentType values are handled better now (Bug 459474).
  • A tutorial section on User Tracking has been added to Help (Bug 844823).
  • The Customize Headers window prompted twice (Bug 524662).
  • ReplyTo has been added to the default IMAP headers in order to fix Reply with Template behavior (Bug 655428).
  • The offline folder flag will no longer be set for SPAM and TRASH folders (Bug 809990).
  • Help now includes documentation for the Offline Applications pref pane (Bug 771534).
  • The main Privacy & Security pref pane is now documented and features a Help button (Bug 631566).
  • The access key for "Perform these actions" now sets/moves focus to first action item in the Filter editor (Bug 825449).
  • Clear Private Data (preferences and menu) documentation has been added to Help (Bug 416234).
  • An "Error parsing template: expected to be first" message could appear when opening the virtual folder list dialog (Bug 747325).
  • The umask for emails saved as a file were not respecting the system umask (Bug 472865).

New in SeaMonkey 2.18 Beta 2 (Apr 22, 2013)

  • Some parts of click-to-play did not work if doorhangers were disabled (Bug 860537).
  • The Open Link in New Window context menu item had stopped working in MailNews (Bug 860905).
  • The browser feed preview had been broken due to Private Browsing changes (Bug 856322).
  • Per-site click-to-play permissions had stopped working (Bug 854867).
  • An LDAP password was requested for each lookup even if it was saved (Bug 833971).
  • Creating/amending mailing lists in the Address Book had been broken (Bug 859068).
  • The tabbed browser uses the favicon service in a privacy-aware way now (bug 856406).
  • The Open Location dialog does not save the state anymore when opened from a private window (bug 844497).
  • Private downloads did not update (bug 849440).
  • Save As from the context menu did not take the privacy status into account (bug 851304).
  • Added icons for security notifications (bug 853268).
  • Fixed the browser feed preview to work with XBL scopes (bug 846763).

New in SeaMonkey 2.17 (Apr 4, 2013)

  • Continued performance improvements around common browser tasks (page loads, downloads, shutdown, etc.).
  • Continued implementation of draft ECMAScript 6 (clear() and Math.imul).
  • now supports blend modes.
  • Various and improvements have been implemented.
  • The Details button on the Crash Reporter has been fixed (bug 793972).
  • Fixed several stability issues.

New in SeaMonkey 2.16 (Feb 21, 2013)

  • Reply to List is now supported.
  • SSL-related warning prompts (leaving or entering a secure site, viewing mixed content) have been replaced by less intrusive, non-modal notification bars.
  • See the changes page for minor changes.

New in SeaMonkey 2.15 (Jan 9, 2013)

  • SeaMonkey-specific changes:
  • SeaMonkey can be set as default client/browser on Mac and Linux now.
  • See the changes page for minor changes.
  • Mozilla platform changes:
  • Preliminary support for WebRTC has been added.
  • Image quality has been improved through a new HTML scaling algorithm.
  • CSS3 Flexbox has been implemented.
  • Support for new DOM property window.devicePixelRatio has been added.
  • Support for @supports has been added (disabled for now).
  • Startup time has been improved through smart handling of signed extension certificates.
  • HTML5: Support for W3C touch events has been implemented, taking the place of MozTouch events
  • Insecure content loading has been disabled on HTTPS pages (see bug 62178).
  • Fixed several stability issues.

New in SeaMonkey 2.10 (Jun 7, 2012)

  • SeaMonkey-specific changes:
  • The domain name is highlighted in the location bar by default now, configurable in Preferences.
  • The amount of tabs to be restored concurrently can be configured in Preferences now.
  • News username and password auth dialogs have been combined and show for which server the prompt is now.
  • Mozilla platform changes:
  • The new minimum supported Windows version is now XP SP2, Windows 2000 support has been dropped.
  • The SPDY protocol now enabled by default for faster browsing on supported sites
  • The column-fill CSS property has been implemented.
  • Experimental support for ECMAScript 6 Map and Set objects has been implemented.
  • Support for the CSS3 background-position property extended syntax has been added.
  • The :invalid pseudo-class can now be applied to the element.
  • The CSS turn unit is now supported.
  • Fixed several stability issues.

New in SeaMonkey 2.6 Beta 1 (Nov 28, 2011)

  • Added Print Preview support to Composer
  • Added update channel indication to About SeaMonkey page (about:)
  • Mozilla platform changes:
  • Added Type Inference, significantly improving JavaScript performance
  • Added support for querying Do Not Track status via JavaScript
  • Added support for font-stretch
  • Improved support for text-overflow
  • Improved standards support for HTML5, MathML, and CSS
  • Fixed several stability issues

New in SeaMonkey 2.1 RC2 (Jun 7, 2011)

  • Sync (f.k.a. Weave) is now included directly in SeaMonkey. Sync allows you to keep your browsing history, passwords, bookmarks, preferences and tabs in sync across different devices (computers) in a secure way.
  • SeaMonkey windows can now be themed with Personas (lightweight themes).
  • The bookmarks system has been reworked to use the Places framework shared with Firefox (already used for history data in SeaMonkey 2.0), including a new Bookmark Manager and fast bookmarking button in the location bar.
  • Find in Page now works with a toolbar instead of a modal window.
  • OpenSearch plugins are now supported and the default for web search.
  • An optional search bar (including suggestions if the search engine supports it) is available in browser toolbar customization, and an engine manager for OpenSearch is available.
  • More toolbar widgets are now customizable.
  • The new Add-ons Manager opens directly in the browser now and has received a major facelift.
  • The new Data Manager now unifies cookie, permission, password, and form data management.
  • Flash cookies (LSOs) will now be removed when using Clear Private Data / Cookies (requires Flash Player 10.3 or better).
  • Plugin crashes do not take down the whole application anymore since plugins run in their own processes now.
  • Plugins now work in feeds shown in MailNews windows.
  • The feed preview UI and the Helper Applications preferences can now detect the system's default feed reader and use it.
  • Page zoom is being remembered on a site-specific basis now.
  • The browser tab bar is now scrollable to cope with tab overflow. This includes an "All Tabs" navigation button to quickly list all open tabs.
  • You can now drag and drop downloads, e.g. from the Download Manager to the desktop.
  • SeaMonkey now shows "doorhangers" for notifications like remembering log-in passwords or after installing an extension.
  • The new DoNotTrack HTTP header is supported (configurable in Preferences).
  • A page with Troubleshooting Information (about:support) and the option to restart in Safe Mode are now available from the Help menu.
  • Loading the URL about:memory now shows how much memory is used by different parts of SeaMonkey.
  • SeaMonkey should now support more websites that previously appeared to only work with Firefox (configurable in Preferences).
  • Built-in extensions (ChatZilla, JavaScript Debugger and DOM Inspector) are now installed into the profile.
  • News messages can now be deleted from local storage.
  • Cascaded Session Restore improves restoring large browsing sessions.
  • SeaMonkey now uses Omnijar which results in fewer installed files, less fragmentation and better startup time.
  • Platform-specific changes:
  • On Linux, desktop notifications (e.g. mail alerts, finished downloads) show up in the native environment.
  • Mozilla platform changes:
  • Better performance on startup and shutdown, and memory usage improvements.
  • Protection from out-of-date plugins has been added.
  • Text areas in web forms are now resizable.
  • CSS :visited selectors have been changed to block ways that websites can quickly check a user's browsing history.
  • The WOFF format for downloadable website fonts is now supported.
  • SMIL animation in SVG is now supported.
  • New CSS attributes such as gradients, background sizing, and pointer events have been implemented.
  • A new HTML5 parser is used for all HTML documents.
  • New DOM and HTML5 features including the Drag & Drop API and the File API are now supported.
  • JS-ctypes support has been improved, allowing in-application JavaScript code to access native system libraries.
  • HTML5 video can now be viewed full screen and supports both the WebM format and the "buffered" property.
  • Web developers can animate content using CSS Transitions.
  • The W3C Indexed Database API is now available to websites.
  • JavaScript is faster than ever with the new JägerMonkey engine.
  • Support for WebGL, Direct2D and Direct3D acceleration on Windows has been added (see about:support for support and Preferences for configuration).
  • The HSTS security protocol and the proposed Audio Data API are available.
  • OpenType support has been improved.
  • HTML5 Forms API support has been added.

New in SeaMonkey 2.1 Beta 3 (Apr 8, 2011)

  • When you start SeaMonkey in Safe Mode, you are now presented with a dialog that allows you to permanently apply some of the Safe Mode changes. Furthermore you can enter Safe Mode directly from the Help menu now.
  • If a plugins crashes, you are now presented with several options right there (e.g. reloading the page).
  • Built-in extensions (ChatZilla, JavaScript Debugger, DOM Inspector and DebugQA) are now installed into the profile.
  • SeaMonkey Sync supports the easy setup process (J-PAKE) now.
  • Windows 7 Jump Lists support was added.
  • Outdated plugins are detected now.
  • Tabs can now be switched using mouse scrolling (in addition to scrolling the tab bar).
  • WebGL support via ANGLE has been added.
  • An optional search bar (including suggestions if the search engine supports it) is available in browser toolbar customization, and an engine manager for OpenSearch is available.
  • The delete action in the MailNews Advanced Search dialog has been fixed.
  • Plugins now work in feeds shown in MailNews windows.
  • ChatZilla is working again.
  • The JavaScript Debugger Venkman is working again.
  • Download progress is now shown in the Windows 7 taskbar.
  • Cascaded Session Restore improves restoring large browsing sessions.

New in SeaMonkey 2.0.9 (Oct 20, 2010)

  • Security fixes
  • Fixes for a number of non-security-relevant crashes, increasing the stability of the whole platform and the Mail & Newsgroups part of SeaMonkey

New in SeaMonkey 2.0.7 (Sep 8, 2010)

  • Security fixes
  • Message-ID searches on Google Groups work again
  • Add-ons preferences button for Lightning should work now

New in SeaMonkey 2.1 Alpha 2 (Jul 8, 2010)

  • New Add-ons manager (bug 561600)
  • Drag URL/file to/from SeaMonkey's Download Manager (copy/move to desktop/folder) (bug 192728)
  • Save multiple messages as individual files in directory (bug 555972)
  • Make Search, Folder Location and Views widgets for MailNews customizable toolbars (bug 521927)
  • WebM video is now supported for HTML5 tag. (bug 566245)
  • View source is now consistently taken from the platform and appearing in a SeaMonkey look and feel across all invocations. (bug 411754)
  • Loading the URL about:memory now shows how much memory is used by different parts of SeaMonkey.
  • SeaMonkey now supports a lot of the same tabbrowser API as Firefox. (bug 467867)
  • Search and Go buttons widgets for Browser are now customizable. (bug 529647)
  • The feed preview UI and the Helper Applications preferences can now detect the system's default feed reader and use it. (bug 471346)
  • HTML5 Websockets are now available to website authors. (bug 472529)

New in SeaMonkey 2.0.4 (Mar 30, 2010)

  • Browser:
  • Closing browser / switching profile keeps and later restores state / open tabs and history (Bug 486696)
  • MailNews:
  • Null pointer dereference or redundant check in mailnews/mime/src/mimei.cpp. (Bug 532108)
  • gloda indexes while offline, if we startup without a network connection (Bug 533776)
  • Autocomplete - primary email address no longer appears before additional email address (now sorted alphabetically) (Bug 543088)
  • Port Bug 410996 - Answering a news article in a saved search folder not stored under a news account creates mail reply instead of follow-up (Bug 546040)
  • Reply button doesn't launch mail composition window. (Bug 549802)
  • crash [@ nsMsgSearchValidityTable::GetAvailable(int, int, int*)] in matchAll filters using saved search or updating filters (Bug 514945)
  • crash [@ nsImapMailFolder::UpdateImapMailboxInfo(nsIImapProtocol*, nsIMailboxSpec*)] (Bug 531792)
  • Too many .msf file open with many third level folders and Show only subscribed folders unchecked/disabled (Bug 549794)
  • WARNING: goofy tree selection state: two ranges are adjacent!: 'endFirstRange == startRange' with test_delete_multiple_messages_with_first_selected_message_open in test-deletion-with-multiple-displays.js (Bug 540252)
  • crash [@ nsMsgXFViewThread::AddHdr(nsIMsgDBHdr*, int, unsigned int&, nsIMsgDBHdr**)] manipulating messages in virtual folder (Bug 539784)
  • crash [@ NS_strlen(unsigned short const*)] - [@ nsImapProtocol::ShowProgress] with IMAP and Galician locale. (Bug 506669)
  • ChatZilla:
  • Langpack incompatible with SM version > 2.0 (Bug 540842)
  • Certificates & Security Features:
  • Update Mozilla stable branches to NSS 3.12.6 and minimal support for RFC 5746 (Bug 545755)
  • General:
  • [SeaMonkey] FTP file upload not working (Bug 467524)
  • Update Help on Popup Windows preferences (Bug 543332)
  • Remove repetitions (the, of) from Help (Bug 543336)
  • Turning Encryption On and Off is no longer an option, remove it from Help (Bug 543340)
  • Remove last traces of Quick Launch from Help (Bug 545765)
  • # mochitest-plain: intermittent "Test timed out" in security/ssl/mixedcontent tests (test_bug329869.html, test_bug383369.html, test_bug455367.html, test_bug472986.html) (Bug 517938)
  • # Override NSS database path for xulrunner application (Bug 462919)
  • # 'make clean' deletes automationutils.py (Bug 525047)
  • # [Linux] mochitest-plain: layout/xul/base/test/test_resizer.xul needs to report success (Bug 492481)
  • # Crash when pasted selection contains data from java [@libc-2.10.1.so@0x729b8 ][@ nsClipboard::HasDataMatchingFlavors] [@ nsHTMLEditor::HavePrivateHTMLFlavor] (Bug 495392)
  • # crash [@ _pushpopupsenabledstate() ] (Bug 528900)
  • # SwitchProxy triggers a Firefox crash in [@ PL_DHashTableOperate] PREF_PrefIsLocked (Bug 535990)
  • # Print dialog should not display the SVG output option when printing to a file (Bug 546093)
  • Compiling:
  • client.py should error out early if wrong python version (Bug 537571)
  • [Tracking] Resync' configure.in between c-1.9.1 and m-1.9.1 (Bug 496236)
  • Port |Bug 473411 - the rule for DIST_FILES should create dist/bin| to c-c (Bug 543294)
  • Port |Bug 422986 -- make -j2 -f client.mk profiledbuild fails| to comm-central (Bug 543296)
  • Remove MOZ_VALGRIND from comm-central (Bug 545133)
  • Port |Bug 495224 - Builds involving symlinks in the source dir fail to find config/config.mk| to comm-central (Bug 545594)
  • Port |Bug 509319 - Enable FIPS throws uncaught exception in toggleFIPS| to comm-central (Bug 548210)
  • Missing python version check in configure (Bug 548670)
  • Require python >= 2.4 to build Mozilla (and >=2.5 on Windows hosts) (Bug 427750)
  • Fix bsdiff linking for builds compiled with CROSS_COMPILE (Bug 535369)
  • Allow client.py network attempts to restart itself in case of failures (Bug 538528)
  • Package new layers library on shared builds (Bug 549390)
  • Hourly/Nightly builds should have some way to see which changeset was used (Bug 474610)
  • Platform:
  • mochitest-plain: test_domWindowUtils.html fails intermittently (Bug 513146)
  • Scrollbars are not being update using dss.enabled (Bug 546941)
  • vorbis_analysis_headerout calls oggpack_writeclear with uninitialized ogb if !v->backend_state (Bug 550184)
  • TM: Severe performance deterioration of String.match with complex regex (Bug 502058)
  • extend nsIINIParser to allow writing INI files (Bug 541594)
  • Update info should allow more html tags through (Bug 503505)
  • Integrate BrowserScope's HTML editor test suite with Mozilla's mochitest framework (Bug 550569)
  • file drop URIs only accidentally work (Bug 549349)
  • Comment out nsw.gov.au in PSL (Bug 547985)
  • nsPluginHost::TrySetUpPluginInstance() can return with the plugin instance owner holding a non initialized instance. (Bug 533030)
  • Hang [@ nsRegion::InsertInPlace] with position:fixed (Bug 541869)
  • Malian registrar (.ml) allows second-level domains (Bug 544319)
  • crash [@ nsHTMLAnchorElement::UnbindFromTree(int, int)] (Bug 540953)
  • Moving FILE_ILLEGAL_CHARACTERS from nsCRT.h to nsCRTGlue.h for frozen linkages (Bug 537967)
  • C++ style comment in C unit modules/plugin/default/unix/npunix.c (Bug 548213)
  • cp932 encoded messages display as garbage (Bug 542823)

New in SeaMonkey 2.0 Beta 2 (Sep 14, 2009)

  • tabbed mail, enabling accounts, folders and even single messages to be opened in tabs inside the Mail & Newsgroups window, as well as enabling the Lightning extension to be installed into SeaMonkey for calendering functionality.
  • a completely renewed default theme on Mac OS X to better fit with the look of Leopard and Snow Leopard,
  • reopening of closed browser windows (Undo Close Window),
  • introduction of simpler interfaces for extension developers (SMILE),
  • and a large number of other, smaller improvements.

New in SeaMonkey 2.0 Alpha 2 (Dec 11, 2008)

  • Major Changes:
  • SeaMonkey switched to Toolkit, the same backend Firefox uses internally. Due to this change SeaMonkey is now much closer to Firefox as far as user profiles, add-ons and functionality of user interface elements are concerned.
  • The default location of user profiles has changed. Legacy profiles, e.g. from SeaMonkey 1.x, are migrated automatically, excluding third-party add-ons (extensions and themes). The old profile will not be touched (instead, copies are made).
  • The new Add-on Manager allows to install, update, disable and remove extensions (add-ons), themes and plugins using the same mechanisms Firefox uses. This should ease extension management and development considerably.
  • The first step towards customizable toolbars has been made: The icon size and whether to display icons and/or text can be chosen separately for every major toolbar in in both the browser and MailNews components via their context menu.
  • The MailNews component now includes support for reading RSS and Atom feeds, And the browser detects feeds offered by web pages. Since the support for previewing feeds in the browser has not yet been included, the feed icon at the right end of the URL bar currently is directly invoking subscription to the feed in the MailNews component, if an account for feeds has already been created there.
  • Gecko, the rendering engine used in SeaMonkey, has seen many improvements since the version used in the last stable release. Changes range from a better graphics backend (Cairo/Thebes) to improved support for fonts, CSS, DOM and JavaScript. SeaMonkey 2.0 Alpha 1 passes the Acid2 test and most of Acid3.
  • Most of the icons in the default theme have been exchanged for newer images that fit better with the look of modern desktop environments.
  • Support for Windows 95, 98, Me and NT 4 was dropped. GTK 2.10 is now required on Linux/UNIX. Support for Mac OS X 10.3 ("Panther") was also dropped.
  • Browser:
  • Add Undo Close Tab (Bug 350416, Bug 354953)
  • Introduce Info Bars (e.g. used when popups or add-on installations are blocked) (Bug 270443)
  • Allow to reload individual images using the context menu to aid dialup users canceling page loads (Bug 47475)
  • Remove the font download dialog (Bug 352049)
  • Add full zoom capability (zooming images and objects as well as text) (Bug 4821)
  • Port new Firefox page info to SeaMonkey (Bug 379183)
  • Beautify FTP/File/Jar/Gopher directory listing (with new layout, icons and sortable columns) (Bug 294800)
  • Add "Send This Link" to link context menus (Bug 137007)
  • Save form inputs' state with Save Page As (Bug 293834)
  • Switched to a better graphics backend (Cairo/Thebes), improving display of all web content and application chrome significantly (Bug 322938)
  • Acid2 test renders correctly in most cases (Tracked in Bug 289480)
  • Lots of improvements to Acid3 test rendering (Tracked in Bug 410460)
  • Support WHATWG and tags (Bug 382267)
  • Implement cross-site XMLHttpRequest (Bug 389508)
  • MailNews:
  • Rename TLS and SSL in SMTP preferences to what they really mean (STARTTLS, SMTP-over-SSL) (Bug 185662)
  • Make Reply, Reply All, Forward and Next buttons dual-mode (adding Reply to Sender, Reply to All Recipients, Forward Inline/As Attachment, Next Message/Flagged Message/Unread Thread) (Bug 17796)
  • Do not lose keystrokes while email composer is saving draft (Bug 352310)
  • Speed up deleting attachments containing UNIX line breaks (Bug 365751)
  • Add "Stop Filter Execution" filter action (Bug 358684)
  • Allow to set marking junk as read independently for automatic and manual cases in preferences (Bug 377920)
  • Do not fall back to insecure authentication after SMTP authentication failure (Bug 311657)
  • Support opening a message from the command line (Bug 386919)
  • Remove "Copy Folder Location" context menu entry, moving functionality to Location field in Properties dialog (Bug 369393)
  • Add ability to select IMAP trash folder (Bug 182274)
  • Allow user to reorder newsgroups using drag&drop (like in NS4) (Bug 150274)
  • Display clickable references for newsgroup messages (Bug 62033)
  • Show new newsgroups in Subscribe dialog (Bug 40260)
  • Spell check the subject line when composing mail (Bug 391964)
  • Show folder address in Folder Properties dialog (Bug 180546)
  • Implement mail "back" and "forward" (Bug 74959)
  • Make local body search work when mail body is encoded as Base64 (Bug 132340)
  • Show text in multipart messages with empty Content-Type (sent by Outlook) (Bug 155537)
  • Allow to filter news based on any headers (Bug 16913)
  • Make delete message work if header of message preview pane has focus (Bug 419379)
  • Allow to do a complete import (settings, mail etc.) at any time (Bug 399312)
  • Get rid of the Send in UTF-8 question dialog, just silently switch to UTF-8 if necessary (Bug 410333)
  • Allow to kill/ignore a news subthread (branch, not the whole thread) (Bug 11054)
  • Add "Recent Folder Target" to Move and Copy menus (Bug 416669)
  • Allow renaming of already-attached attachments (Bug 190298)
  • Make sure IMAP code does not deadlock when it cannot reach the network (Bug 410747)
  • Persist message priority across moves after changing it via filter (Bug 181561)
  • Add a pref to decide whether to quote text attachments in replies (Bug 384599)
  • Limit growth of junk token store (and thereby memory) (Bug 228675)
  • Speed up displaying saved searches with lots of results (Bug 436960)
  • Add a way to entirely disable marking a message as read when viewed (Bug 297534)
  • Add ability to show only IMAP mails that have not been deleted (Bug 190974)
  • Load IMAP/news messages from memory (if present) when offline (Bug 213729)
  • Use better chunk size calculation when mail.imap.fetch_by_chunks is active (speed up sending of large emails) (Bug 425849)
  • Quote just the selected portion of a message during Reply (Bug 23394)
  • Allow signature to be placed above the quoted text when forwarding messages (Bug 273114)
  • Improve online IMAP experience by using pseudo-offline Delete and Move (decouple IMAP operations from UI changes) (Bug 435153)
  • Allow filter of "To or CC" to use "is in Address Book..." and "is not in Address Book..." (Bug 187768)
  • Make Get All New Messages work with Movemail accounts (Bug 278383)
  • Enable filters to move mail after copying it (Bug 376235)
  • Add confirmation dialog for Empty Trash action (Bug 179891)
  • Rename 'Unsent' folder to 'Outbox' (Bug 387656)
  • Allow to specify whether to run filters when checking mail, run manually, or both (add a separate manual filter context) (Bug 440635)
  • Add ability to filter only selected messages in a folder (Run Filters on Selected Messages) (Bug 444209)
  • Play back tags to IMAP server when switching from offline to online (Bug 141606)
  • Add ability to show just the name and not the email address in the message pane (Bug 309057)
  • Allow to change IMAP expunge threshold using a pref (Bug 399835)
  • Implement auto-expunge for IMAP mailboxes (Bug 359284)
  • Enable Mac OS X system address book per default and add UI (Bug 397811)
  • Disable JavaScript in MailNews for now (Bug 453943)
  • Make IMAP folders offline by default if they are newly created and mail.server.default.offline_download pref is true (Bug 452615)
  • Add ability to download IMAP messages preemptively/automatically in the background (Bug 436615)
  • Add birthday fields to address book (Bug 13595)
  • Enable threaded/grouped-by-sort views for saved searches across multiple folders (Bug 379806)
  • Fix importing mail from Outlook 2003/2007 (Bug 408323)
  • Port Thunderbird RSS/Atom reader to SeaMonkey (Bug 255834)
  • Allow extensions to add custom filter actions (Bug 419356)
  • Mark message as read when deleting it from local folder (or POP/IMAP when offline) (Bug 463849)
  • Do not collect addresses into Collected Addressed that occur in other ABs (Bug 58769)
  • Certificates:
  • Allow to export certificate or full chain in Certificate Viewer (Bug 315871)
  • Introduce error pages (and ability to create exceptions) for invalid-certificate errors (Bug 327181)
  • Allow configuring used certificate per mail identity (Bug 278549)
  • Implement new security exception handling backend for MailNews (Bug 429843)
  • Introduce new certificate error page which better separates user information from technical details (Bug 463504)
  • ChatZilla:
  • Change Switch Text Direction shortcut to Ctrl+Shift+X (was: Ctrl+Shift+E) (Bug 333570)
  • Do not open multiline input when dropping link in single line input (Bug 332588)
  • Add IRC-Hispano to default network list (Bug 227366)
  • Add IRCnet to default network list (Bug 135926)
  • Allow styling all parts of ChatZilla with motifs (Bug 235169)
  • Allow disabling Bugzilla link detection on a per-channel basis (Bug 349137)
  • Allow to reorder tabs using drag and drop (Bug 194913)
  • Add auto-away feature (Bug 382085)
  • Display WALLOPS messages (Bug 379087)
  • Support multiple selected users with context menu commands (Bug 408527)
  • Display IRCX ONJOIN messages (Bug 303631)
  • Make double clicking user open query view (WHOIS) (Bug 432235)
  • Display all-numeric channel names as links (Bug 433703)
  • Do not discard changes when topic edit mode focus is lost, add Cancel button (Bug 399450)
  • DOM Inspector:
  • Allow inserting/creating new nodes (Bug 112775)
  • Add File / Save DOM As... (Bug 72494)
  • Allow to hide processing instructions (Bug 360898)
  • Show separate menu entries for Inspect Content/Chrome Document (Bug 337069)
  • Add ability to pick open pages (as opposed to open windows) (Bug 109481)
  • Offer DOM Inspector as an add-on on AMO (Bug 271812)
  • Windows:
  • Create a new Windows installer based on NSIS (Bug 351917)
  • Support new shell service for setting SeaMonkey as default application (better Vista integration) (Bug 380347)
  • Remove "turbo mode" (quick launch) (Bug 361682)
  • Make Debug QA and Palm Sync extensions optional in Windows installer (Bug 385377)
  • Make ChatZilla optional in NSIS installer (Bug 409490)
  • Support "? queryterm" from the command line (launch the default search engine and search for 'queryterm') (Bug 408248)
  • Create UI for new shell service (setting as default application and mail/news handler) (Bug 441050)
  • Enable .wdseml (Windows Search indexer) file opening support for Mail/News (better Vista integration) (Bug 433697)
  • Let downloaded files inherit NTFS properties (like permissions, compression, encryption) from parent directory (Bug 224692)
  • Cleanly unload in case of exiting or restarting Windows (Bug 212316)
  • Linux:
  • Let Backspace default to nothing on Linux instead of going back (in history) (Bug 358764)
  • Support startup notification on Linux/UNIX desktops (Bug 223492)
  • Enable native theme (form control etc.) in HTML content on Linux (Bug 329846)
  • Add support for the X Session Management Protocol (XSMP) (Bug 93789)
  • Make Copy Image work on Linux (Bug 21747)
  • Show preview of files in GTK file picker (Bug 396876)
  • Let $http_proxy influence proxy settings (Bug 66057)
  • Respect the user's settings of icons in menus (Bug 415810)
  • Support Internet keys (Bug 66519)
  • Map mouse buttons 8-9 to back/forward (Bug 355477)
  • Use Gnome's native print dialog on Linux (Bug 193001)
  • Remove XPrint (Bug 326716)
  • Enable DBUS by default on Linux (Bug 388743)
  • Bump minimal required GTK2 version to 2.10 (Bug 420040)
  • Allow dragging bookmarks from a folder in the Personal Toolbar (Bug 151336)
  • Map mouse buttons 6-7 to horizontal scrolling on Linux (Bug 423563)
  • Make drag and drop of graphics insert the image instead of the URL (Bug 229327)
  • Make Mark All Read keyboard shortcut Ctrl+Shift+C on Linux (like on Windows; was: Ctrl+Shift+M) (Bug 422757)
  • Allow dragging multiple image files onto editor (Composer; MailNews and stand-alone) window (Bug 428876)
  • Add a globally shared location for plugins (/usr/lib/mozilla/plugins) on Linux/Unix (Bug 440506)
  • Mac OS X:
  • Do not try to import IE favorites on Mac (Bug 433117)
  • Make Cmd+T open a new window when no browser windows are open (Bug 429926)
  • Move caret to beginning/end of url bar or text box when pressing up/down arrow key (Bug 231754)
  • Improve Mac installer (.dmg) (Bug 406448)
  • Implement Mail.app importer in MailNews core (Bug 420472)
  • Implement Mail.app / 4.x Mac Communicator like versions of the "move/copy" menus (Bug 178091)
  • Enable Mac OS X system address book per default and add UI (Bug 397811)
  • Make Dock icon show new mail at the same time as the Growl alert (Bug 459482)
  • Add Growl integration for mail alerts on Mac OS X (Bug 308552)
  • Compiling:
  • Introduce MozillaBuild for Windows (Bug 363079)
  • Make Mozilla compile with Microsoft Visual Studio 2005 (VC8) (Bug 249782)
  • Remove non-Cairo GTK2 gfx code (GTK 1 support and Xprint) (Bug 383889)
  • Build Chatzilla as an extension (Bug 351715)
  • Remove support for --enable-extensions=all (Bug 450015)
  • General:
  • Add "Ignore Word" to inline spellchecker used for editable elements (Bug 354580)
  • Use bullets instead of asterisks to block out password characters (Bug 97811)
  • Make dictionaries part of the locale pack in the installer (Bug 350688)
  • Make a backup copy of prefs.js before overwriting it if there were errors reading it (Bug 361102)
  • Make downloading using "Save Link As..." successful on a link to a page/file that uses HTTP/FTP authentication (Bug 315227)
  • Allow multiple selection of text with Ctrl (Bug 73373)
  • Switch backend from XPFE to Toolkit (Bug 328887)
  • Add command line handlers for Toolkit (makes -remote work on all platforms) (Bug 335550)
  • Update Software Installation preferences pane including options for automatic updates of the application and add-ons (Bug 363700)
  • Remove Appearance / Themes preferences pane (moved to Tools / Add-on Manager) (Bug 372856)
  • Make Debug/QA UI an extension (that can be disabled or removed) (Bug 381343)
  • Offer to migrate Thunderbird profiles (Bug 306175)
  • Use FF/TB's extension mechanism (Add-on Manager and backend) (Bug 272429)
  • Add migrator for old profiles (Mozilla Application Suite and SM 1.0/1.1) (Bug 329744)
  • Replace Quality Feedback Agent by Breakpad crash reporter (Bug 383125)
  • Use FF's form manager (satchel, was: wallet), including form field autocompletion (Bug 304309)
  • Replace MySpell with HunSpell spelling checker (Bug 319778)
  • Provide mechanism to allow users to list, enable and disable plugins in Add-on Manager (Bug 339056)
  • Make text and images translucent while dragging (Bug 178513)
  • Use new English spell checking dictionary (Bug 397150)
  • Enable automatic updates for SeaMonkey (using AUS) (Bug 408190)
  • Make Plugin Finder Service work with SeaMonkey (replacing Null Plugin) (Bug 278831)
  • Disable direct input of filename into file upload controls (Bug 258875)
  • New icon set for "SeaMonkey Default Theme" (Bug 348720)
  • Add sanitize (clear private data) option (Bug 416233)
  • Add new Helper Applications preferences pane (Bug 417590)
  • Integrate addons.mozilla.org (AMO) into Add-ons Manager (Bug 414918)
  • Implement geolocation prompt (notification bar) (Bug 459413)
  • Enable view-source link-browsing (SRC, HREF) (Bug 17612)
  • Use Toolkit Type Ahead Find instead of the old one (Bug 345526)