[polux]

(Disclaimer: I'm partly working on Dart)

- Every Javascript program is a valid typescript program so typescript doesn't fix JS semantics (like variable hoisting and the only numeric type being floats). I think typescript is a good fit when you already have some big JS project and you want to get some type errors by loading a predefined signature for jquery or whatever library you're using. You basically get a linter + code completion for free on a pre-existing project. But if I have the choice between Javascript and any other language with saner semantics to start a new project, then I will for sure not chose Javascript.

- I don't think that Dart aims to "replace the entire JacaScript runtime in all browsers", even though the Ars Technica article says so. It's an alternative to Javascript, exactly like Ruby is an alternative to Python. Of course there's a difference between Js vs Dart and Python vs Ruby: every browser runs Js and only Js. That's why the story with Dart is: develop with the VM and Dartium, so that you can reload you application with F5, use the debugger, etc. and then deploy by compiling to Javascript.

[MatthewPhillips]

Function hoisting is a good thing.

[polux]

Sorry, what do you mean by function hoisting? The fact that you can write mutually recursive functions at toplevel? Anyway, I was referring to variable hoisting.