Mozilla has released the fourth beta of Firefox 3.5, whose design includes improved performance and better stability, as well as a private browsing mode.
Firefox 3.5 beta 4 has already been delayed several times and now is tentatively slated to ship before the end of June.
As it usually does, Mozilla warned users that Beta 4 is suitable for testing only. "Firefox 3.5 Beta 4 is a public preview release intended for developer testing and community feedback," said Beltzner. We recommend that you read the release notes and known issues before installing this beta."
The beta's release notes highlighted several still-unfixed issues with Firefox 3.5, including problems with Gmail, Google's popular web-based email service, and with parts of the new privacy feature.
Beta 4 is the first major milestone of Mozilla's new browser to carry the "3.5" moniker; originally, the upgrade was called Firefox 3.1, but the company decided it had added enough new features to justify the larger bump in version number from last summer's Firefox 3.0.
Although Mozilla said much earlier in the Firefox 3.5 process that it would ship a limited number of betas before moving on to a "release candidate," it's unclear today what Mozilla's next step will be. Attempts to reach Beltzner via email were unsuccessful.
In 2008, the company issued the last beta of Firefox 3.0 in early April, and the final version in mid-June. Assuming Firefox 3.5's pace is similar, Mozilla should ship Firefox 3.5 sometime in early July.
Firefox 3.5 Beta 4 can be downloaded for Windows, Mac OS X and Linux in 63 different languages from Mozilla's site. Users already running Beta 3 will be notified of the available update in the next 48 hours.