ES - ES6 Harmony (ES2015)

ECMAScript 6 (also known as ES2015).

The first ECMAScript Harmony specification, it is also known as ES6 Harmony

• class declarations (class Foo { … })
• ES6 modules import
• arrow function expression (() ⇒ {…}),
• let keyword for local declarations,
• const keyword for constant variable declarations,
• …

See added features

Babel - https://babeljs.io/docs/learn-es2015/

• https://mail.mozilla.org/pipermail/es-discuss/2008-August/006837.html
• See http://wiki.ecmascript.org/