Mozilla Firefox 3.6 Beta 3
Windows, Mac, Linux: Firefox 3.6 beta 3 bundles up over 80 bug fixes from the last beta but at the same time it drops some of its marvels like tab preview.
It maintains others like alerting users about out-of-date plugins, and built in support for Personas. This is certainly the fastest of the 3 betas released so far, it is released in 60 different languages and will certainly undergo many more changes before the first release candidate.