Mozilla has some articles on ES6 (JavaScript) features that look interesting:
- ES6 In Depth: The Future
- ES6 In Depth: Modules
- ES6 In Depth: Subclassing
- ES6 In Depth: let and const
- ES6 In Depth: Classes
- ES6 In Depth: Proxies
- ES6 In Depth: Generators, continued
- ES6 In Depth: Collections
- ES6 In Depth: Using ES6 today with Babel and Broccoli
- ES6 In Depth: Symbols
- ES6 In Depth: Arrow functions
- ES6 In Depth: Destructuring
- ES6 In Depth: Rest parameters and defaults
- ES6 In Depth: Template strings
- ES6 In Depth: Generators
- ES6 In Depth: Iterators and the for-of loop
- ES6 In Depth: An Introduction