Ars Technica points out that the organization has released the first beta of Firefox 3.1, its next major browser release. You can grab the beta right here on mozilla.com in Windows, Mac OS X, and Linux flavors. Little has changed compared to Firefox 3 from a cosmetic standpoint, although you'll encounter new features like the graphical tab switcher (brought up by hitting CTRL-TAB with a few tabs open). Mozilla developers seem to have focused the bulk of their efforts on under-the-hood changes, like the addition of the TraceMonkey JavaScript rendering engine. TraceMonkey isn't on by default because of reliability concerns, Ars says, but you can enable it by typing "about:config" in the address bar, finding the "javascript.options.jit.content" variable, and setting it to "true."

The beta includes Mozilla's new TraceMonkey JavaScript engine, which uses tracing optimization to deliver a massive performance boost that makes it faster than Google Chrome's V8 engine. TechReport took the new engine for a spin through the SunSpider JavaScript Benchmark on a Core 2 Duo E6400 system with 4GB of RAM and Windows Vista x64, and we found that it bested both Google Chrome and the latest stable Firefox release (3.0.3). The Firefox 3.1 beta scored 1873.0ms, slightly ahead of Chrome's 2212.2ms and well past Firefox 3.0.3's 3792.6ms. It's not just benchmarks, either-TraceMonkey makes GMail and iGoogle feel incredibly snappy. The Mozilla guys reportedly think TraceMonkey has room for extra optimizations, so the final Firefox 3.1 release might be even speedier.