Dart has been around for a while now and it's gotten some traction. Google supports it with Dartium, a Chromium version with a built-in Dart VM.
In the meantime, Google continues to expand the language and the tools around it, the latest addition being a Web UI library which, as the name suggests, aims to make it easier for developers to create UI elements with Dart.
"Built on Web Components, and inspired by Model Driven Views, Dart's Web UI library is now ready for testing," Google explained
"This early release of Web UI supports dynamic templates, live one-way and two-way data binding, and custom DOM elements. Web UI also includes a compiler that makes these features available to all modern browsers today," it added.
The Web UI has some pretty nice elements which should make designing web apps a lot simpler and a lot cleaner. It also "enhances" HTML code making it possible to add interactive elements with very little code.
Google has some examples
of what the Web UI library can do and has also updated the Dart Editor to support it.