Mozilla Launches Final Firefox 3.0 Beta

Firefox 3.0 Beta 5 landed on Mozilla’s download servers on Wednesday.

Mike Beltzner, Mozilla’s interface designer, highlighted several changes to the open-source browser, including improved UI integration with the underlying operating system, performance gains from additional changes to the JavaScript engine, and an unspecified number of bug fixes and modifications for features new in Firefox 3.0, such as the full-page zoom and bookmark backup and restore.

Beltzner also called out other speed optimizing changes “to improve performance over previous releases as measured by the popular SunSpider [JavaScript] test from Apple, and in the speed of Web applications like Google [ Gmail ] and Zoho Office.”

Beta 5’s release was delayed somewhat by the discovery last week of a serious bug in the Mac version of the browser, which required fixing before Mozilla would sign off on the preview.

Updated release notes also published today noted that Beta 5 includes more than 750 changes since the rollout of Beta 4 about three weeks ago.

Last Beta

Today’s beta will be the last for Firefox 3.0, Mozilla’s chief engineer has said, and developers will be moving on to Release Candidate 1 (RC1). In notes from a Monday meeting that have been posted to the Mozilla Web site, the code-freeze date for the release candidate has been set as next Tuesday.

Mike Schroepfer, Mozilla’s vice president of engineering, said last week that he expects Firefox 3.0 to run through three release candidates before the final version. Mozilla has targeted June for delivering the browser.

Firefox 3 Beta 4 can be downloaded for Windows, Mac OS X and Linux in 40 languages from Mozilla’s site .

However, as has been its practice with every beta, Mozilla again warned casual users against using the preview. “Firefox 3 Beta 5 is a developer preview release of Mozilla’s next generation Firefox browser and is being made available for testing purposes only,” the release notes read.

Mozilla Fixes 10 Firefox Flaws, Half Seen as ‘Critical’

Mozilla patched 10 vulnerabilities, half of them marked “critical,” in its open-source browser as it updated Firefox to version 2.0.0.13. The new Mozilla Messaging spin-off, however, was not able to provide a matching update to its Thunderbird e-mail client, which shares five of the Firefox flaws that were fixed.

Mozilla’s six advisories spelled out five Firefox bugs marked “critical,” three tagged “high” and one each “moderate” and “low.”

“There’s a little bit here to interest most everyone,” said Andrew Storms, director of security operations at nCircle Network Security. “The bulletins claim no favor in the many types of vulnerabilities typically associated with browsers.”

Among the critical flaws were a pair that could be exploited to crash the browser or its JavaScript engine, and perhaps do more. “Some of these crashes showed evidence of memory corruption under certain circumstances and we presume that with enough effort at least some of these could be exploited to run arbitrary code,” Mozilla wrote in the advisory pegged as 2008-15.

Mozilla also patched potential identity leaks, spoofing bugs and cross-site scripting vulnerabilities in 2.0.0.13. But the fix that caught Storms’ eye was detailed by 2008-18, a fix for LiveConnect, a feature that harks back to Firefox’s predecessor, Netscape Navigator. LiveConnect lets Java applets call a Web page’s embedded JavaScript, or JavaScript access the Java runtime libraries, and is used by both Firefox and Apple Inc.’s Safari 3 browser.

“Sun has updated the Java Runtime Environment with a fix for this problem. Mozilla has also added a fix to LiveConnect to protect users who don’t have the latest version of Java,” Mozilla said in the advisory.

“Here we have Firefox putting out a mitigation step for a bug in Java,” said Storms. “It’s a welcomed addition when one vendor can help out another.”