Update 6:15 p.m. PST: An earlier version of this story said the second beta version of Firefox 3.1 would likely be the last. Firefox is planning a third beta version. Also, added a comment from Paul Rouget about when the second beta version will likely be released.
The second beta version of Firefox 3.1 is "due out very shortly," Mozilla programmer Ben Turner said Thursday.
One big change in the 3.1b2 is the addition of "Web workers," a feature that lets the browser process tasks in the background. That feature, part of the still-evolving HTML 5 specification, adds another level of sophistication for programmers writing Web applications and gives multicore computers a better way to use their processors' abilities.
"We've been hard at work with folks from Google, Apple, and others to get this new spec nailed down," Turner said of the Web workers work.
Google and Apple also build their own browsers, as does market-leading Microsoft and ever-scrappy Opera. With the browser wars back in full force, those organizations are racing to outdo each other on features and performance.
In a post on the Mozilla Add-ons Blog, Paul Rouget said: "Firefox 3.1 Beta 2 will likely be released the first week of December." He added: "We have added a Beta 3 to our schedule."