Those improvements for the Windows, Apple OS X and Linux versions of the software are achieved in several ways. One of the biggest performance enhancing additions in Firefox 7 (code named Aurora) is the introduction of MemShrink, which Mozilla hopes will change Firefox's reputation as a memory hog.
MemShrink can reduce Firefox 7's memory usage by anywhere from 20 to 50 percent, according to Mozilla, and improve performance in responsiveness, startup and page load times. You can download the .
With MemShrink, Firefox 7 memory usage will remain constant for long periods of time and closing many tabs will free up more memory. "This means that Firefox 7 is faster (sometimes drastically so) and less likely to crash, particularly if you have many websites open at once and/or keep Firefox running for a long time between restarts," Nicholas Nethercote, a Mozilla developer in Melbourne, Australia, explained in .
Better Garbage Collection
Another change aimed at boosting performance is better JavaScript garbage collection. It works more frequently now to free up memory faster and improve performance when many tabs are open at the same time.
Firefox 7 implements Azure Direct2D for Canvas, too. That speeds up canvas-based animation rendering in HTML5.
There are also additions to help developers speed up how the browser reacts with their offerings. A Web timing spec allows developers to measure page load times and site navigation so they can boost their website's performance. And a CSS3 overflow function gives developers a way to display text that overflows the layout area on a page.
Mozilla has also improved synchronization of bookmarks and passwords in this release of the browser--synchronization is faster--and has introduced a telemetry add-on to help Mozilla gather browser data that can be used to improve future releases of the program.
Android Changes
As with the Firefox versions for other operating systems, the Android beta version of the browser has better memory optimization and synchronization, but it has a few other enhancements, too. Text can be copied and pasted from mobile websites, for instance, and a previous session's history and tabs will be restored on startup.
Language support has also been improved. Now, during set up, Firefox will detect the language setting on an Android device or offer a selection of up to 10 languages during the process, .
Firefox 7 for Windows, OS X and Linux can be for free from Mozilla. The Android version of the browser is available for from the Android Market.
The primetime release of Firefox 7 is expected to be ready on September 27.
And the Beta Beat Goes On
Meanwhile, Firefox 8 is expected to enter the pipeline this week. A prominent feature in that version of the software will be . That prevents any add-ons from being installed in the browser unless they're approved by a user.
"[T]hird-party applications frequently install bundled add-ons into Firefox as part of their own installation process," Mozilla explained in its Add-Ons blog. "While some of these applications seek the user's permission beforehand, others install add-ons into Firefox without checking to make sure the user actually wants them"
"These add-ons installed by third parties present a number of problems: they can slow down Firefox start-up and page loading time, they clutter the interface with toolbars that often go unused, they lag behind on compatibility and security updates, and most importantly, they take the user out of control of their add-ons," it continued.
"That's why we're introducing two new features to ensure users have complete control over their add-ons," it added.
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