Learning JavaScript

Below is reference material about JavaScript that is recommended for learning about performance, good practices and advanced patterns.

Performance

 * Grokking V8 closures for fun (and profit?) and http://mrale.ph/ in general gives you a great understanding of how V8 optimizes JS internally.
 * The bluebird optimization killer page has a lot of practical advice.

ES6

 * ECMAScript 6: new OOP features besides classes

Basics
Just got started learning to program, or want to start now? Then these may be more relevant for you instead.