[zoechi]

This is an interesting question. Almost any language is better than JavaScript. JavaScript is fine for small event handlers in a guestbook sized app but for more complex applications it's just a PITA (I didn't say it isn't possible to build more complex apps though).

'Incredible immature' is plain wrong. Dart is quite mature.

The biggest disadvantage is the availability of libraries (packages) but otherwise it is very comfortable to work with. There are already packages for most requirements but the available selection is still small and they often don't have all the features you are looking for.

To your question: A few points are listed here http://stackoverflow.com/questions/7712107 or https://www.dartlang.org/support/faq.html