It sounds like Mozilla is having good luck improving JavaScript performance with [TraceMonkey](http://weblogs.mozillazine.org/roadmap/archives/2008/08/tracemonkey_javascript_lightsp.html). See also Andreas Gal's [paper on Trace Trees](http://www.ics.uci.edu/~franz/Site/pubs-pdf/ICS-TR-06-16.pdf).

Are these improvements available to other interpreters/compilers and if so, does this mean we'll see a cascade of improvements in other interpreted languages?