Believe it or not, the release of Firefox 3.1 has slipped all the way into March 2009. However, the next Beta build of Firefox 3.1 is now just around the corner, with Mozilla looking to finalize the development milestone come next week. On February 25, 2009, there were 10 show-stopping bugs still preventing Mozilla form signing off Beta 3, and with them out of the way the open source browser will be able to advance to its fourth Beta.

“The continuing and great work on fixing other final-release blockers means that we're accumulating a lot of changes on the 1.9.1 stream that would benefit from wider feedback from our beta testers. To that end, we're going to wrap up beta 3 in the next week (...); a 4th beta will follow approximately 6 weeks after, as a vehicle for more testing of tracemonkey, video, places and other eagerly-awaited improvements as well as feedback from beta 3,” Mozilla's Director of Ecosystem Development Mike Shaver stated.

Firefox 3.1 Beta 3's release will come approximately three months after the availability of the second Beta for the open source browser. Mozilla made Firefox 3.1 Beta 2 available for download in the first half of December 2008, and was estimating that the browser would move to the Release Candidate stage as the next development milestone. This seems to no longer be the case with talk of Beta 4 pushing Firefox 3.1 consistently back into 2009.

At the same time, Shaver acknowledged the need to discuss whether or not Firefox 3.1 should become Firefox 3.5. It was done before, when Firefox 1.1 evolved into Firefox 1.5. Given the weight of the updates introduced into Firefox 3.1, Shaver indicated that the scenario in which the next iteration of Firefox would be 3.5 instead of 3.1 will be put up for discussion following the availability of Beta 3.

“We are going to be extremely conservative here, using the criteria that we use for non-blocker approvals. To get in, a feature will need to be: complete: no follow up fixes or initial implementations that commit us to extending the schedule further; proven: patches with tests, security reviews and performance impact analysis, baked on trunk for a good amount of time; valuable: we need to understand the benefit of taking the change, and why it's needed for 3.1 instead of later; removable: blackout-ready, if anything goes wrong,” Mike Beltzner, Mozilla User Experience lead, stated.

There are, at this point in time, no less than 120 blockers, show-stopping bugs that remain to be fixed before Firefox 3.1 or 3.5 will be finalized.

Firefox 3.1 Beta 2 for Windows is available here.

Firefox 3.1 Beta 2 for Linux is available here.

Firefox 3.1 Beta 2 for Mac OS X is available here.