Meet Firefox 3.1 Beta 2

Firefox 3.1 Beta 2 is officially available. The release marks the first time Mozilla’s super-speedy TraceMonkey Javascript engine is enabled by default and also includes several new features that had been under development for some time, such as Firefox’s Private Browsing Mode and new functions to target specific browsing times or URLs to remove from your history.

Firefox 3.1 Beta 2 also marks the debut of web worker thread support and support for video and audio tag elements. Other under-the-hood additions include the W3C Geolocation API, JavaScript query selectors, CSS 2.1 and 3 properties, SVG transforms, and offline applications. A full list of added features is available here.

The new beta is available for Windows, Mac OS X, and Linux. There’s one more step before the final release — Mozilla decided a couple of weeks ago to go for a third beta prior to finishing the new Firefox. Beta 3 is expected to come out in early January, with the full 3.1 release to follow soon after.