Mozilla on Wednesday announced it would ship the final version of Firefox 4 on March 22.
Originally scheduled to ship last November, Firefox 4 will wrap up a development cycle that started in February 2010 with several developer previews, but began in earnest last July when Mozilla released the first of what would eventually be a dozen betas.
Wednesday, Mozilla developers called the current Release Candidate, or RC build of the browser, good enough to ship as the final. Traditionally, it has run through multiple release candidates before settling on the latest as the shipping code. More than a year ago, for example, Mozilla issued two release candidates of Firefox 3.6.
"Today's triage session concluded with all systems go for a Firefox 4 launch on March 22," said Damon Sicore, Mozilla's senior director of platform engineering, in a message on a company forum.
Mozilla CEO Gary Kovacs congratulated the troops on the same forum.
"We set a goal in December, we stressed toward the goal. At times, many thought we, I, us, were crazy, or too aggressive... but in the end, we were able to get it done in March," Kovacs said.
Firefox 4 will reach users eight days after Microsoft issued Internet Explorer 9 (IE9).
Before it began cranking out Firefox 4 betas, Mozilla had set an aggressive schedule that was to end with a final edition no later than November 2010. Last October, however, the open-source developer admitted it had underestimated several bugs, and said it was delaying the release until 2011.
Firefox 4 features a new tab manager, dubbed "Panorama," supports GPU acceleration to boost page composition speeds and boasts an overhauled interface that resembles Chrome's and IE9's minimalist designs.
Mozilla is already prepping for the next version of Firefox. According to plans now circulating among developers, the company is considering an ambitious schedule that will ship a major upgrade every three or four months.
Firefox 4 is Mozilla's best shot at reclaiming some of the browser usage share it's lost in the last year. Recent statistics from web analytics company Net Applications had Firefox's share at 21.7% in February, down from 24.5% 12 months before.
Anyone running Firefox 3.5 or 3.6 can grab the upgrade March 22 by selecting "Check for updates" from the Help menu. Users running Firefox 4 RC, however, won't need to download anything next week because Mozilla deemed that build identical to the final.