[coldtea]

Speak about Python and Ruby.

Javascript is insanely fast, with V8 and its ilk.

And I'm not talking about "toy benchmarks" either, I'm talking about envolved stuff written in plain JS (no C extensions), from the QT port to JS/Canvas, to the h264 encoder and such. Try doing those on Python and you'll see what you get. And of course all the toy benchmarks also agree.

Javascript with v8 is like a faster PyPy (with less performance deviation): 10 to 20 times faster than plain Python code.

Sure, you can extend Python with fast C code. But as the core languages are concerned, JS beats CPython hands down. (Oh, and you can also extend JS with fast C/C++ code if you need that. Node modules do it all the time).