You have it backwards. There's no reason for browsers to choose CoffeeScript or TypeScript because they do not change the semantics of JavaScript which make it hard to optimize for. There really isn't anything for a browser to adopt with one of those languages, other than a small translation to JS.

Dart is fundamentally different in that it was designed for speed (as well as toolability and readability) and by directly supporting Dart a VM can make many more optimizations than a JS VM can. The Dart VM is already 1.5-2x faster than JS in some cases, while being _much_ younger.

In what way is Dart "so far behind" CoffeeScript?

developer mindshare.

Check tag count for questions on SO; 4500 for CoffeeScript, 1500 for Dart.

Not to mention the violent revulsion many people (myself included) are expressing in this topic.

By that metric, GWT blows away CoffeeScript with ~15,000 questions on SO. Are you sure you want to use that metric?

Point was to compare compile-to-javascript languages.

Uh, GWT is a Java-to-JS compiler.

On that note, Java has 508,338 questions on StackOverflow, which crushes CoffeeScript, /especially/ with those 15,000 GWT questions ;)

Oh, interesting. Is it really a standalone transpiler or is it a set of tools?

As someone else pointed out, SO isn't a great metric, but finding github activity by language seemed to take more time than I was willing to invest.

No metric will be great right now because Dart is so new compared to CoffeeScript. CoffeeScript 1.0 was released 3 years ago. Give us a chance to get 1.0 out the door :)

That's not a very good metric. CoffeeScript is twice the age of Dart.

Fair point; I was trying to get github numbers and got sidetracked.

> Not to mention the violent revulsion many people (myself included) are expressing in this topic.

Immaturity seems like a good explanation of that effect

Not your best work.

I just let Occam do the dirty work for me sometimes.

Oh don't be so simple.

:P