Mozilla developer centre released its Firefox 3.1 Alpha 2 today. Codenamed as Shiretoko Alpha 2, developers or testers who would like to give it a try can download it. This Alpha 2 release it built on the pre-release version of the Gecko 1.9.1 platform and it introduces a few interesting new features such as:

• Support for the HTML 5 <video> element
• Initial support for web worker threads
• You can now drag and drop tabs between browser windows
• New selector to create areas of Aero-style “glass” in XUL
• Support for CSS 2.1 properties: ::before and ::after, and white-space:pre-line
• Support for CSS 3 properties: -moz-border-image, word-wrap: break-word, text-shadow, box-shadow and column-rule
• Performance improvements and new preference values for color management profile support

Users can download Firefox 3.1 Shiretoko Alpha 2 via the following links:

Windows: Shiretoko Alpha 2 Setup.exe
Mac OS X: Shiretoko Alpha 2.dmg
Linux: shiretoko-alpha2.tar.bz2

Users are also encouraged to read the detail release notes from Mozilla.

Update: Firefox 3.1 Beta 2