I'm surprised that you didn't mention GWT or Script#. GWT is more popular than Volta, Script#, and JSC combined.
I'm surprised that you didn't mention GWT or Script#
I completely forgot about Script#, thanks!
TraceMonkey isn't the first to JIT/cache to accelerate web apps (Bass mentioned this earlier, too).
These optimizations are largely (but not completely) irrelevant to Web programming