(disclaimer, I work on the Dart team)

Thanks for the question!

We released Dart as a Technology Preview last year, which means we released very early in the project's life cycle. We've been collecting feedback and updating/refactoring the language, libraries, and tools. We've recently started releasing Milestone builds, which are essentially beta builds of the SDK and tools. The language does not anticipate backward breaking changes (but we still anticipate adding features like mixins). The libraries are currently undergoing changes, driven by feedback from the community and internal users.

The question if you should use Dart now depends on when you need to ship your projects. Too much will be changing to bet on it to ship your project in Q1 2013. However, my impression is that if you're shipping in Q2 or after, Dart should be a good bet.

The Dart community and team is standing by to help if you have any questions or concerns. You can find us at misc@dartlang.org, dartbug.com, and Stack Overflow.

None within google.

Dart is targeting HTML 5 capable browsers and ECMAScript 5 capable browsers... which tends to means stuff that is current as of today. As google tries to run on some older browsers as well, dart is not a good solution.... yet.

There are teams within google that are starting to build sites with it, but nothing is public yet.

From: http://support.google.com/mail/bin/answer.py?hl=en&answe...

"In general, Gmail supports the current and prior major release of Chrome, Firefox, Internet Explorer and Safari on a rolling basis."

I interpret this as IE10 and IE9, at least for Gmail.

Blossom.io seems to be using Dart [1, 2].

[1] http://news.ycombinator.com/item?id=4694645

[2] https://plus.google.com/113104647883788326011/posts/RzYVrLRs...

Yes we do. One of our first small Dart codebases is the signup widget for our upcoming book.

https://www.blossom.io/growth-engineering

But we're also working on other stuff to ship. Stay tuned :)

Or have anyone just used it and found stable/mature enough to build commercial projects?

(disclaimer: I work on the Dart team)

Good question!

The language does not anticipate backwards breaking changes (modulo any bugs we find in the spec), though we expect to add features like mixins.

The libraries are going through changes now, especially with the introduction of the new Streams API: http://news.dartlang.org/2012/11/introducing-new-streams-api...

The time is good to check out Dart and let us know what features you need for your next commercial project. However, with the libraries evolving right now, I probably wouldn't use Dart for something I need to ship in Q1 of 2013.

We love feedback, and there are a ton of features what work today (package manager, compiler to JavaScript, editor, etc) so we hope to hear from you soon :)

Out of curiosity: what do you feel that Dart provides that makes you consider it (over say other ->JS solutions in the front end and Nodejs on the back)?

Are you even considering using it on the back end?

This answer might help: http://programmers.stackexchange.com/questions/164273/does-d...

Also, performance is looking good: https://www.dartlang.org/performance/