Mozilla has announced the release of a new beta build for the long-time coming Firefox 4. Unlike the last couple beta releases which mostly just tweaked a few things here and there, this one actually brings along a couple of new features to get you excited. Most notably, it incorporates the JagerMonkey JIT compiler into the new SpiderMonkey engine, which will the browser a performance boost on script-heavy sites.
According to the company's internal benchmarking, Firefox 4 Beta 7 is three times faster than the current Firefox 3.6.12 on both Kraken and Sunspider JavaScript benchmarks, and five times faster than Firefox 3.6.12 on the V8 benchmark. The updated browser is also neck-and-neck with competing browsers in terms of performance.
Firefox 4 beta 7 is a "feature complete" beta so a few other things have changed besides JavaScript rendering. There's an upgraded URL bar which now shows the destination of hyperlinks as soon as you hover above a link, updates to the password manager and Panorama (previously known as Tab Candy), a search feature that works across open tabs, better support for hardware acceleration, and brings support for OpenType, a font format that allows for richer, more "book like" typography on the web. Lastly, Firefox 4 beta 7 also includes an add-on API that has been deemed complete enough for third-party developers to begin porting over their creations from older versions of Firefox.
If you're already running a previous beta of Firefox 4 you should see an automatic update soon. Otherwise, if you would like to download beta 7 for Windows, Mac or Linux 32-bit 64-bit, just choose your operating system.