Consider using Typescript

[damylen]

Typescript is a super-set of javascript which allows you to use upcoming javascript features (es 6,7) now. It's compatible with existing javascript code and adds features like better type support (classes/interfaces). It also enables better intellisense, refactoring, compile time error checking, etc.

It is open-source, started by Microsoft, but even Google is using it to develop Angular2.

More info:
http://www.typescriptlang.org/