The Mozilla Project has posted the third beta of Firefox 3.0 for Mac, Linux, and Windows. This is code named "Gran Paradiso". "Firefox 3 is based on the new Gecko 1.9 Web rendering platform, which has been under development for the past 28 months and includes nearly 2 million lines of code changes, fixing more than 11,000 issues. Gecko 1.9 includes some major re-architecting for performance, stability, correctness, and code simplification and sustainability. Firefox 3 has been built on top of this new platform resulting in a more secure, easier to use, more personal product with a lot under the hood to offer website and Firefox add-on developers. [Improved in Beta 3!] Firefox 3 Beta 3 includes approximately 1300 individual changes from the previous beta, including fixes for stability, performance, memory usage, platform enhancements and user interface improvements. Many of these improvements were based on community feedback from the previous beta." I recommend skipping this release unless you need to test your own site. It's been breaking some Web-2.0ish sites.
