I installed a beta version of the Google Chrome browser for Mac the other day. I forget just where I found it, but it was probably linked from something linked from MacHeist which Charley mentioned on his blog. At any rate, while looking through the Help page I ran across a page of Javascript benchmarks.
When I looked at that page in Chrome, I got something like
Score: 3696
Richards: 3663
Delta Blue: 3875
Crypto: 3224
RayTrace: 5585
EarleyBoyer: 6534
RegExp: 1026
Splay: 5499
The latest Safari, which I just downloaded from Apple Software Update, 4.0.4 (5531.21.10) has
Score: 2068
Richards: 2530
DeltaBlue: 2154
Crypto: 2154
RayTrace: 3844
EarleyBoyer: 3085
RegExp: 1024
Splay: 1134
Firefox 3.5.5 shows
Score: 318
Richards: 1270
DeltaBlue: 83.4
Crypto: 784
RayTrace: 189
EarleyBoyer: 298
RegExp: 178
Splay: 400
Does that mean that Chrome is about half again as fast at processing Javascript as Safari, and ten times as fast as Firefox??