ES6
[A detailed overview of ECMAScript 6 features] (https://babeljs.io/docs/learn-es2015/)
[Airbnb의 ES6 자바스크립트 스타일 가이드] (http://firejune.com/1794/Airbnb%EC%9D%98+ES6+%EC%9E%90%EB%B0%94%EC%8A%A4%ED%81%AC%EB%A6%BD%ED%8A%B8+%EC%8A%A4%ED%83%80%EC%9D%BC+%EA%B0%80%EC%9D%B4%EB%93%9C)
[Understanding ES6] (https://github.com/sgaurav/understanding-es6/blob/master/README.md)