A few days ago, I have reviewed Firefox 3.1 Beta 3. It's quite lovely. It boasts improved Javascript performance, it comes with new usability and privacy features, it supports future HTML multimedia elements ... But nowhere in that article did I mention the memory usage. For a good reason.

Firefox 4 is the fastest Firefox yet. With dramatic speed and performance advancements across the board, Firefox is between two and six times faster than previous releases. Major enhancements to the JavaScript engine make everything from startup time to page load speed to graphics and JavaScript performance screaming fast in Firefox.

For most users, Firefox doesn't use an abnormally large amount of memory. For others, however, Firefox's memory consumption is a major problem (Especilaly for people using old computers with limited memory resources), in same cases memory usage in Firefox is due some to other sources, like number of plug-ins, themes and extensions.

According to a recent study by extremetech.com, Firefox 8 is already 20% faster than Firefox 5 in almost every metric and has got a drastically reduced memory footprint as well.

With the release of Firefox 3.5 right around the corner and the inclusion of the new Tracemonkey javascript engine, I thought I'd do a quick javascript performance comparison between the Linux and Windows versions.

Mozilla's high-performance TraceMonkey JavaScript engine, which was first introduced in 2008, has lost a lot of its luster as competing browser vendors have stepped up their game to deliver superior performance. Firefox now lags behind Safari, Chrome, and Opera in common JavaScript benchmarks.

"Please note: Firefox 3 Beta 5 is a public preview release intended for developer testing and community feedback. It includes new features as well as dramatic improvements to performance, memory usage and speed. We recommend that you read the release notes and known issues before installing this beta..." -- ftp://ftp.mozilla.org/pub/firefox/releases/3.0b5/linux-i686/

In Firefox you might have noticed that after opening several tabs and browsing a while system memory starts to be eaten up a lot and performance start degrading a little. Here are some not so obvious tweaks to improving performance.

Mozilla's Firefox 3.0 browser uses memory much more efficiently than its rivals, according to an independent tester who wrote a memory-monitoring utility to track usage by Firefox, Internet Explorer (IE), Flock, Opera and Safari.