Mozilla has released the Firefox 3.0 beta 1, it is available for Windows, Linux and Mac. The release notes states it is currently for testing purposes and aimed at developers, not recommended for normal users. Firefox 3 Beta 1 is available in 20 languages

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.

Mozilla provides Firefox 3 Beta 1 for Windows, Linux, and Mac OS X in a variety of languages. You can get the latest version of Firefox 3 Beta 1.