With Firefox 3.1 Beta 2 still cooking, Mozilla is offering for download the first taste of Firefox 3.1 Beta 3. Just as Microsoft is working its way up to Internet Explorer 8 Release Candidate, so is Mozilla laboring to produce the first RC Build of its open-source browser. And, when it comes down to Firefox 3.1 codename Shiretoko, a couple of Betas are standing between the browser and the Release Candidate stage, namely Beta 2 and Beta 3.

With baking time on Firefox 3.1 Beta 2 almost over, Beta 3 bits can already be grabbed from Mozilla's FTP servers. Mike Beltzner, Mozilla User Experience lead, indicated that inserting the Beta 3 milestone before RC was necessary in order to permit features integrated late into Beta 2 to mature to a sufficient level.

“We don't have full clarity into the nature of our remaining blockers, some of which likely require beta exposure. In order to close this release, a re-triaging (like we did around Firefox 3 Beta 4) is required, both to identify the severity of the remaining blockers and the time required to address them properly. Further, the impact of late Beta 2 landings such as Private Browsing Mode, Worker Threads, Speculative Parsing and TraceMonkey will benefit from multiple beta releases,” Beltzner stated.

“The insertion of another beta also offers another public consultation point for web and add-on developers, allowing us to react to their feedback.”

At this point in time the plan is that Firefox 3.1 will move from Beta 3 directly into Release Candidate stage, a phase which will signal the browser's proximity to finalization. Beltzner indicated that feature additions to Firefox 3.1 would stop with Beta 2. “No new features will be accepted into Beta 3. Limited string changes will be accepted. No add-on compatibility changes will be accepted,” Beltzner revealed.

As of November 26, Mozilla wrapped up the Firefox 3.1 Beta 2 freeze and shifted the focus to Firefox 3.1 Beta 3 pre builds. Release Candidates of Firefox 3.1 Beta 2 are already up for grabs, and Mozilla estimates that the fully fledged Beta 2 Build will become available next week, around December 5.

At the same time, Firefox 3.1 pre-Beta 3 bits can also be accessed, with Mozilla planning code freeze for next year. “Beta 3 code freeze will be scheduled based on the results of the triage, but is expected to be in early January 2009,” Beltzner added.