<i>safari seems to perform much better on a number of them</i><p>The benchmarks on the page are mostly not intended to test relative performance across browsers other than Firefox, and almost certainly do not provide useful comparison data. They were mostly designed to exercise particular performance weaknesses in Firefox, and indicate whether those performance weaknesses are improved by the new code. Micro-benchmarks in the context of very large, complex, systems, are usually pointless...except when going after particular performance issues, as the developers of Firefox are doing.