The latest version of the Firefox Beta branch can be downloaded from Softpedia
Mozilla has officially announced that the second Beta release in the Firefox 22.x branch is now available for download on the Linux platform.The Linux binaries for Mozilla Firefox 22.0 Beta 2 have been made available and you can download it now, without having to install anything.
In the new Firefox 22 Beta 2, WebRTC is now enabled by default, HTML5 audio/video playback rate can be changed, social services management has been implemented in Add-ons Manager, and much more.
The Mozilla developers also improved WebGL rendering performance through asynchronous canvas updates and improved the memory usage and display time for rendered images.
A detailed list of changes can be found in the announcement.
Download Firefox 22.0 Beta 2 right now from Softpedia. Remember that this is a development version and it should NOT be installed on production machines. It is intended for testing purposes only.