Greasemonkey is a handy, free, cross-platform and powerful Mozilla Firefox extension that allows users to easily customize the way a website or a single web page is displayed, as well as to control the way it behaves.
Getting started with Greasemonkey
To install the Greasemonkey add-on on your Mozilla Firefox web browser, you will have to either click the dedicated download button above, add Softpedia to the trusted websites for installing add-ons, download and install the add-on, or via the Mozilla Add-Ons website (https://addons.mozilla.org).
After installation, you will have to restart Mozilla Firefox for the add-on to be functional. After restart, will notice a new button on your toolbar, click it to activate or deactivate with Greasemonkey, manage user scripts, add a new user script, as well as to access user script commands.
In addition, you can access its preferences from the dedicated Add-ons page of the web browser, from where you can enable various functionality, such as secure updates, Firefox Sync support for user scripts, add global excludes, set a default text editor for editing user scripts, and to modify the new user script template.
Designed for Mozilla Firefox
Greasemonkey is an open source add-on designed to work with Mozilla Firefox 29.0 or later, as well as with the Epiphany and Flock web browsers. However, the Greasemonkey extension for Epiphany is distributed as part of the Epiphany-extensions package.
The add-on has been successfully tested with both 32-bit and 64-bit installations of the Mozilla Firefox web browser, supported on all GNU/Linux distributions, as well as on the Microsoft Windows and Mac OS X operating systems.