> Then there's Dart, which is kind of their version of CoffeeScript/TypeScript/etc.
From my point of view, it's just the next logical step after GWT and Closure. The annotations are baked into the language's syntax, you get the usual JS-like development cycle (save -> F5), and Java/C#-like tooling.
TS is somewhat similar. CS, however, isn't. CS doesn't offer any tooling advantages over JS.
> looks strikingly like Angular at times
Heh. There is also a Dart version of Angular:
There are definitely overlapping concerns, but they've dogfooded Angular for both the YouTube TV[1] portal as well as their DoubleClick site, and so I don't think it's just for external purposes.
1. https://www.dartlang.org/polymer-dart/