While I realize that Flash is no longer in vogue these days, ActionScript 3 is a really nice language and I'm surprised nobody else has mentioned it. It provides things like optional static typing for speed improvements, code clarity, and improved tooling/refactoring, as well as classes and packages for organizing larger code bases. It's more of what Brendan Eich envisioned JavaScript 2 to be.
That said, Apple is making it really hard for developers to choose it for all but intranet apps (for which it's really well suited).
I second GWT and the responses here have prompted me to look into CoffeeScript, so thanks for asking this!
That said, Apple is making it really hard for developers to choose it for all but intranet apps (for which it's really well suited).
I second GWT and the responses here have prompted me to look into CoffeeScript, so thanks for asking this!