Dart is a language and a platform behind it. It's really easy do develop advanced applications in Dart and then translate them to javascript. But you are also able to run it in a separate VM.
Those graphs show the opposite. DartVM is the fastest among the three "dart, js, dart2js", then comes Dart2js due to highly optimizable generated code, then handwritten javascript
Well, Start uses another project called Hart [1] template engine that has syntax similar to Slim or Jade. And I'm going to include Gloss [2] there too, it's a CSS preprocessor, but it's not stable yet.
Yeah, and in that sense it's unsurprising - witness how v8 is still typically much, much slower than native C - but emscriptem does surprisingly well.
Essentially, no human word use unhandy, verbose, hard to read syntax whereas a compiler might. Thus in practice the JS subset that handwritten code uses is different from that of compiler generated code.
Yes, these libraries are very good, but they don't generate "@keyframes", Anima does in CSS mode.
And as far as I see they have no parallel animations like http://lvivski.github.com/anima/example/parallel.html. The ball moves forward with lenear timing-function, and up/down with ease-quad, so is slows down when on top and speeds up when falls down
By the way it's the only to support physics in animations