The graph of library growth is stunning: http://modulecounts.com/ For all of JS quirks it is clearly getting something(s) very right.
Yeah, it's available in the browser. I'm not even trying to slam JavaScript--I sort of like it for all of its foot-guns, but this is literally the only reason worth considering for its success. Edit: I like several things about JS. Certainly if it didn't have first class functions, or easy object literals, that would be a pain. Likewise, if it didn't have insane implicit conversions and painful APIs, that would be gr…
Or easy interop (JSON), object and array literals?
JavaScript has more going for it than platform ubiquity.