Since 2010 the development of Dart has been a very successful visionary research project. The implementation has continued throughout the years in a stedy curve. 

What people should know, is that the ideology behind Javascript was somewhat ingenious regarding JSON and prototyping. Dart was somewhat ingenious in terms of language specification, including all kinds of data structures and optional typing, recognizing every term correctly but also give an interpreter and a compiler.

Dart incorporates almost all favorible features of an object oriented programming language as well as eliminating design flaws as they could be regarded in e.g. Javascript.