This is a neat Github repository that is a page discussing all of the new features in ES6, also known as ECMAScript 2015. Basically all of the new features in Javascript.
https://github.com/lukehoban/es6features
Here is a Github.io page that shows a support matrix of which browsers, servers and compilers support which ECMAScript features. It shows ES5, ES6, ES7 and non-standard. It even shows what the currently used browser supports.
http://kangax.github.io/compat-table/non-standard/
