Firefox launched a new release candidate for the next major update to the browser, version 3.5. Firefox 3.5rc3 includes several new features and other changes from prior releases, including:

• This release candidate is now available in more than 70 languages.
• Improved tools for controlling your private data, including a Private Browsing Mode.
• Better performance and stability with the new TraceMonkey JavaScript engine.
• The ability to provide Location Aware Browsing using web standards for geolocation.
• Support for native JSON, and web worker threads.
• Improvements to the Gecko layout engine, including speculative parsing for faster content rendering.
• Support for new web technologies such as: HTML5 <video> and <audio> elements, downloadable fonts and other new CSS properties, JavaScript query selectors, HTML5 offline data storage for applications, and SVG transforms.

Please note that a release candidate is not a fully supported release -- Firefox calls it a "sneak peak." Stick with the current version (3.0.11 for Mac OS X as of this writing) if you have an aversion to bugs and other beta-software oriented issues.

The new released is based on Gecko 1.9.1 rendering engine, and is available for Mac OS X, Windows, and Linux. The Mac OS X version is a 17.6MB download.