Haxe has all your pros and more... Static typing with type inference, OO, good tooling, good libraries, has JS externs for most big libraries and easy JS inter

Haxe has all your pros and more... Static typing with type inference, OO, good tooling, good libraries, has JS externs for most big libraries and easy JS interoperability, IDEs with good tools (including a fantastic VIM plugin called Vaxe), etc... And of course Haxe also has its own platform, or can compile to native code... Just saying. Of course Dart has Dartium, which could one day be the future...