Mozilla has admitted that Firefox 3.0 Beta 4 is essentially up in the air. There are effectively no plans in terms of the schedule of Firefox 3.0 Beta 4, at this point in time. Mozilla is already pressing on with the final details for Firefox 3.0 Beta 3, but as far as the next step in the evolution of the upcoming version of the open source browser is concerned, the steps associated with the building of Beta 4 are yet to be decided. With Firefox 3.0 Beta 2 out since December 2007, Mozilla has moved onward with the development of Beta 3.

On January 29, 2008, Mozilla announced the code-freeze stage of Firefox 3.0 Beta 3, a phase planned to take no longer than a week. In this regard, as early as the week of February 11, end users and testers should be permitted access to the full Beta 3 bits, following the delivery of a few Release Candidate builds. In fact, as early as February 4, Mozilla has wrapped up the first Release Candidates for Firefox 3.0 Beta 3.

"After a successful freeze & bake period, the tree was closed at 5:20 PST for tagging. The build team returned control of the tree and started spinning RC builds for Firefox 3 Beta 3. The tree status and Firefox Tinderbox page have been updated to reflect the checkin rules for this point forward: any fix for a bug marked blocking-firefox3+ or blocking1.9+ may land (as long as it doesn’t modify strings, as per the l10n freeze); any patch marked with approval1.9+ may land and tests and NPOTB for Firefox patches may land. Also, there will be some delicate landings (memory allocation work, JS optimizations) over the next few days which will require that we close the tree in order to be able to fully monitor tests and performance," Mozilla stated.

But despite the fact that development of Firefox 3.0 Beta 3 is progressing at a fast step, and despite the existence of plans for the upcoming milestone, the schedule for Firefox 3.0 Beta 4 has not been put together.