New Firefox 4

After a short delay, Mozilla released the next version of its browser (firefox), with many bugs fixed, increased speed, and support for CSS Transitions.

Coming 20 days after first beta of firefox 4, this Firefox 4 beta 2 missed last week's targeted release date because of needed quality assurance tests. Beta 3 is tentatively expected to hit on August 6, and the first release candidate is slated for October.

This second beta doesn't offer any drastic changes in design or functionality from what my firefox 4 beta 1 revealed, but the Mac version now gets tabs on top the way the Windows version did in beta 1, with Linux to follow at an unspecified date. The new version also lets you turn a tab into an "App Tab" from a right-click context menu when your mouse cursor is over that tab.

The browser, based on the new Gecko 2.0 page layout engine, now lets developers make use of CSS Transitions, part of the draft CSS3 specification. These allow formatting changes to occur over a specified time period instead of instantly, for an animated effect.

Performance has been addressed in the new beta in several ways. Retained layers improve some effects and improve scrolling for some content. JavaScript is speedier, and a change to the XPCOM component framework should help with startup time and process separation. In all, 652 issues have been addressed in beta 2, including things like correcting problems with the new JetPack add-in system, which doesn't require a restart to update extensions, SVG animation fixes, ironing out WebGL, and adding the new web video format from Google.

We can try the new test browser for ourself by heading to the Mozilla site. It's available in 24 languages for Windows, Mac OS X, and Linux. Though Mozilla posts a caveat that it's pre-release software and we may encounter compatibility problems with add-ons, they also report that it's considered stable and safe to use.