[davidlumley]

I think there's a difference between languages designed to compile down to JS (e.g. CoffeeScript) and wanting to convert a completely different language (e.g. Ruby or C#) into JS.

JavaScript has a lot of good and bad parts, and given we don't really have an option of choosing to use something else in its place I strongly believe that (some) languages that compile to JS have their place. While I don't believe all of them are useful (i.e. dart, typescript) they're specifically targetted as an alternative to JavaScript.

If you're trying to convert a different programming language, that isn't based around the way JavaScript does things then I firmly believe you're doing something wrong. JavaScript isn't just remembering that the semi-colon is optional and that JSON is wonderful. While other languages support event driven behaviour, JavaScripts implementation is (probably) different meaning there's still a learning curve. The documentation for Node.js is, unsurprisingly in JS. The libraries are JS. The whole ecosystem is JS. At least with CoffeeScript quite a few libraries have their source as .coffee, and the style of programming is identical to the compiled JS.