> Does it support prototypal inheritance? (also great)

No. Dart has classical inheritance, which by the large number of classical inheritance libraries for Javascript, is still very popular even when prototypal inheritance is available.

I personally abhor prototypal inheritance. It's aesthetically unappealing, hard to reason about, hard to optimise, and turns what is usually a declarative pattern into an imperative one. When most people are approximating classical inheritance anyway, that's a big sign.

It's sometimes nice that objects can differ structurally from their class, but I've never found it that useful.

Every language under the sun has closures and first class function objects now (Even C if you count llvm-specific extensions, and Java if you count one method interfaces as a suitable workaround until version 8).

Also, Javascript's version of prototypal inheritance isn't very good. Name me one thing you can do well with Javascript's inheritance that you can't do well in any other dynamic language with some notion of objects having property dictionaries (Perl, Python, Ruby, Lua, etc.).