Firefox 4 Early Beta Sports HTML5 and WebM Video

The Mozilla Foundation has taken the wraps off Firefox 4 Beta 1, the latest version of its popular Web browser application. Firefox 3.0 came out all the way back in 2008, while Firefox 3.5 debuted last year. Firefox 4 is aimed at addressing a number of performance and stability issues, improving security, adding support for new Web technologies…and giving the browser a new look and feel.

Some of the most significant changes for Firefox 4 are under the hood: the browser is implementing support for HTML 5’s flash-free video playback capabilities using Google’s WebM video format, which purports to be unencumbered by patent obligations. The patent issue is key for Mozilla: the non-profit organization has said it does not intend to support H.264 video—the standard currently supported by the likes of Apple’s iPhone and iPad for Flashless Web video—because of patent issues, even though it’s currently available to license under a royalty-free agreement from the MPEG-LA trade group. Firefox 4 beta 1 also incorporates a new look at feel: tabs have been moved to the top of the browser window to get out of the way of Web content, and Windows Vista/7 users will notice the Firefox menu is a single button. These changes haven’t migrated to the Mac and Linux versions yet, however.

Under the hood, Firefox 4 sports a new HTML 5 parser and attempts to address a number of performance and stability issues. Firefox 4 includes support for graphics hardware acceleration (WebGL is there, but disabled by default), and a rendering technique called “lazy frame construction” which should reduce the number of cases where a document has to be reflowed within a region—something especially helpful with Web-based applications. The application also sports a new Add-ons Manager, and tweaks the should avoid exposing users’ browsing histories. The browser also brings out-of-process-plugins (OOPP) to Mac OS X for the first time, meaning a plug-in crash doesn’t take out the whole browser. (The technique has been used in Apple’s Safari for a while.)

Firefox 4 Beta 1 is still early in development; users should expect the road to be a bit bumpy as the Mozilla team works towards an official release. Mozilla expects to release new betas every few weeks.