Mozilla yesterday released a beta of Firefox 7, putting the lighter-weight browser in front of a large number of users for the first time.
According to Mozilla, Firefox 7 uses significantly less memory than Firefox 4 through Firefox 6, cutting consumption by as much as 50%.
The savings come courtesy of a two-month-old project dubbed "MemShrink" designed to drive down Firefox's memory consumption and close "memory leaks," bugs that prevent memory from being released to the system when tabs are closed. Over time, those bugs can degrade the browser's performance, or in extreme cases, cause it to crash or lock up.
In a blog post 10 days ago, Nicholas Nethercote, the Mozilla engineer who manages MemShrink, said that Firefox 7 "uses less memory..., often 20% to 30% less, and sometimes as much as 50% less" than earlier versions.
Nethercote also claimed that the memory changes make Firefox 7 faster than its predecessors.
The appearance of Firefox 7 in Mozilla's beta channel starts the clock ticking toward a Sept. 27 release of the browser. Mozilla now rolls out new versions every six weeks, adding features to each edition as they're completed rather than waiting for numerous changes to accumulate.
Other improvements in Firefox 7 highlighted by Mozilla include faster synchronization of passwords and bookmarks between copies of the browser, quicker rendering of HTML5 Canvas-based animation on Windows PCs, and a new optional add-on that provides Mozilla with performance data.
Firefox 8, next in the series, will sport some additional memory bug fixes, said Nethercote Tuesday, including one that decreases consumption on very large web pages.
Mozilla said Thursday that it will launch Firefox 8 to the "Aurora" channel some time today. That edition is slated to ship in final form on Nov. 8.
Five months ago, Mozilla shifted to a faster release cadence and a multiple-version program that offers Aurora, beta and release editions -- listed in increasing order of polish and stability -- for testing and evaluation.
The beta of Firefox 7 can be downloaded from Mozilla's website. Users who have been running earlier betas -- such as the one for Firefox 6, which shipped three days ago -- will be automatically offered version 7.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed . His e-mail address is firstname.lastname@example.org.