JS isn't particularly slow any more, thanks to the massive efforts invested in the optimization of the various competing JS engines. It is generally faster than

JS isn't particularly slow any more, thanks to the massive efforts invested in the optimization of the various competing JS engines. It is generally faster than Python 3 (http://benchmarksgame.alioth.debian.org/u64/benchmark.php?test=all&lang=v8&lang2=python3&data=u64 http://benchmarksgame.alioth.debian.org/u64/benchmark.php?te...) and not just a little. Just for the hell of it I compared node and python on naive fibonacci. That is anecdotal, of course, but node is 30 times faster. I do agree with you that JS has horrid, bug-prone semantics, but it's impressively well optimized. I also agree that other languages offer better tools. For instance, Python has Numpy. However, that's written in C++, not in Python. You can write plugins for Node in C++ too, so nothing would stop someone from writing a Numpy equivalent for JS. You might even be able to run it in some browsers through something like Emscripten with a performance overhead of 2-3x (I think?)