There's huge benefits to having just one language to implement, too huge to fragment the browser space any worse than it already is (just try to get consistent results across browsers, even with only "one" language). What's happened is that Javascript as *implementation* is the one way, but you can program in at least Java and Python. Look at
. Both just use Javascript as the "assembly language". You can leverage a lot of the infrastructure of either language in spite of the "only Javascript" in the browser. It's just no one has tried the same for Perl (to my limited knowledge :-)