Mozilla has announced the availability of Firefox 4 beta 7, a prerelease build for users who want to help test the next major version of the popular open source Web browser. It includes JaegerMonkey, Mozilla's enhanced JavaScript engine.

During our tests of the new beta, we were consistently impressed by its outstanding performance and greatly improved responsiveness. It delivers highly competitive performance and puts Firefox back on an even footing with its rivals. The beta also brings the Firefox 4 theming overhaul to Linux, including the new tab position above the address bar.

Windows and Mac OS X users will find that WebGL is enabled by default with supported hardware. Intel graphics hardware isn't supported yet, but will be in the future. Linux users can expect to see WebGL enabled by default in a future beta release. Hardware-accelerated rendering, which is used for certain graphical operations, is working with Direct3D on Windows and OpenGL on Mac OS X.

On the standards front, Mozilla has introduced support for HTML5 forms, which enables sophisticated browser-side form validation. Text input elements now support a "pattern" attribute that Web developers can use to specify a validation regex for the field.

We benchmarked beta 7 on an Ubuntu desktop computer with a six-core Intel i7 980X processor. It blazed through the SunSpider test in a mere 208ms. On the same computer, Chromium 6 took 224ms. Mozilla's efforts to improve JavaScript performance are clearly paying off. The beta also opens and closes nearly as fast as Chrome and offers smoother scrolling and tab switching than the previous version.

Users who want to try out the beta themselves can download it from Mozilla's website. For additional details, you can refer to the official release notes. The final release is expected to arrive next year.