Changes

*[[JavaScript:TraceMonkey|TraceMonkey]], the addition of native-code compilation to SpiderMonkey

*[[JaegerMonkey|JägerMonkey]], a new baseline JIT compiler for SpiderMonkey<br>

*[[Tamarin]], the new virtual machine for [http://www.adobe.com/devnet/actionscript/ ActionScript] that's already in Flash.

*Make mostly-dense arrays [https://bugzilla.mozilla.org/show_bug.cgi?id=322889 blazingly fast]. Latest bug: [https://bugzilla.mozilla.org/show_bug.cgi?id=486356 type-specialized Arrays].