Mozilla releases beta 7 of Firefox 4, claims 3-5x performance boost
Additionally, the latest beta includes a stable add-ons API, so developers can finally update their add-ons to Firefox 4.
In Scott Fulton's Browser Performance tests in October, he ranked Firefox 4 Beta 8 behind both Opera and Chrome, but well ahead of Safari and Internet Explorer. At the time, however, the feature-complete version of Beta 7 was not available for testing.
That milestone has been reached, and it can be downloaded now.
Using the Kraken and Sunspider benchmark test suites, Mozilla says FF4 beta 7 runs 3 times faster than beta 6; and in the V8 Benchmark suite, it counts a 5x improvement.