As Firefox 4 Beta 12 Debuts, Mozilla Looks Ahead to Firefox 5

Mozilla on Friday rolled out what appears to be the last beta release of its Firefox 4 open source Web browser software.

Available for Linux, Mac and Windows, Firefox 4 beta 12 offers numerous improvements to the browser's general stability, performance and compatibility, Mozilla says. Performance is now better while viewing Flash content, for example, as is plugin compatibility when hardware acceleration is enabled.

Several hundred bugs have also been fixed in this latest release, for a total of more than 7000 fixed since the software's first beta version. On the usability end, hovering over a link now displays the URL at the bottom of the window rather than in the location bar.

"We are in the final stages of the Firefox 4 Beta cycle," reads the announcement on the Mozilla Blog.

A release date for the final version has not yet been announced, but a release candidate is due sometime in March, according to the software's roadmap. Mozilla recently announced that it planned to accelerate the software's development cycle, rolling out multiple major releases this year, all the way through version 7.

In the meantime, the new beta version is now available for download on Mozilla's site. More than 400 million people now use Firefox around the world, the company says.

'Tabs on Top' Layout

Firefox 4 has experienced numerous delays in its development cycle, and there have been more beta versions than originally expected. Among the more notable features of the new version are support for "do not track" capabilities along with JägerMonkey, a considerably faster JavaScript engine.

With a new homepage design, Firefox 4 offers a new "tabs on top" layout, and it no longer switches into offline mode automatically. Tabs and add-ons can be managed more easily, Mozilla says, and new synchronization features help keep versions across devices fully up to date.

Multitouch, 3D graphics and the WebM format are all supported, as is hardware acceleration, though problems with drivers have made that feature problematic on Linux.

Firefox 5 Screenshots

Even as Mozilla is wrapping up work on Firefox 4, development is already under way on Firefox 5, the software's next major version.

Indeed, Conceivably Tech recently uncovered notes and a series of mockups suggesting that the next version will feature a more responsive interface, an updated search bar that's 240 pixels wide, and substantial changes to the appearance and use of tabs.

Particularly intriguing, in fact, are suggestions that Mozilla may be planning a "site-specific browser" in which tabs get dedicated to specific sites and which will integrate a navigation menu and site links within a site tab. A visit to Twitter, for example, might then automatically integrate "new tweet," "direct messages" and "mentions" within a drop-down menu on the tab for that site.

Other ideas being considered include new ways of promoting Firefox Sync and blocking automatically installed add-ons.

Currently occupying the No. 2 spot in the worldwide browser market--behind only Microsoft's Internet Explorer--Firefox was recently named the No. 1 browser in Europe. Time will tell whether these exciting new changes will be enough to propel the browser ahead of its competition. In the meantime, Firefox remains my browser of choice.

Follow Katherine Noyes on Twitter: @Noyesk.