Firefox 4 revs its JavaScript engines with JägerMonkey

As the beta release of Internet Explorer 9 looms large, speedy new additions to Firefox 4 promise stiff competition.

Microsoft may be on the verge of releasing the public beta version of Internet Explorer 9, but Mozilla has been busier than ever fortifying its Firefox browser with upgrades and new additions designed to keep it ahead.

The latest improvement? The JägerMonkey JavaScript engine, which promises to propel Firefox ahead when it comes to JavaScript processing.

JavaScript performance is particularly critical for calculation-intensive Web applications and browser-based games.

Though recent beta releases of Firefox 4 have revealed significant improvements in other areas--including the unique Panorama feature that promises to set the browser apart in tab management--most have still lagged behind the likes of Chrome and Opera when it came to JavaScript--until last week, that is.

Preview builds of Firefox now include the JägerMonkey engine and are showing big improvements in benchmark scores.

Winning V8 Scores

Mozilla's last previous major JavaScript engine upgrade was TraceMonkey, which gave Firefox 3.5 a big speed boost.

Since then, however, "the Web has grown more complex, with more and more JavaScript-intensive demos, apps, and games," Mozilla blogger David Mandelin explains in a recent post. "And the competition has been getting a lot tougher, with engines that could run fast on bigger and prettier Web apps. We knew we needed another major upgrade for Firefox 4.0, to make us fast all around."

With JägerMonkey, the new Firefox builds feel significantly faster, especially on JavaScript-heavy applications like Gmail and Facebook, Mandelin reported.

Not only that, but the new builds are achieving winning scores on the V8 benchmark, beating out Internet Explorer 9 Preview 3 and earlier Firefox versions as well as inching much closer to the speeds achieved by WebKit, Opera 10.61 and Chrome 6.0.472.55, according to Mozilla blogger Rob Sayre.

More Speed on the Way

Firefox 4 is also expected to be even faster by the time its final version is released this November, due primarily to improvements now under way to make function calls faster.

Currently in its fifth beta release, Firefox 4 recently gained hardware acceleration as well. Mozilla's browser now occupies the number two spot in the worldwide browser market.

Nightly preview builds of Firefox with JägerMonkey are available for download from the project's site, but they're not recommended for use in production environments.

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Katherine Noyes

PC World (US online)
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