1. ECMAScript 5

    Full support for the ECMAScript 5 specification. Features include `Function.prototype.bind`, Array methods like `indexOf`, `forEach`, `map` & `filter`, Object methods like `defineProperty`, `create` & `keys`, the `trim` method on Strings and many more.

  2. ECMAScript 2015 (ES6)

    Support for the ECMAScript 2015 specification. Features include Promises, Modules, Classes, Template Literals, Arrow Functions, Let and Const, Default Parameters, Generators, Destructuring Assignment, Rest & Spread, Map/Set & WeakMap/WeakSet and many more.

  3. Object.entries

    The `Object.entries()` method creates a multi-dimensional array of key value pairs from the given object.

  4. Object.observe data binding

    Method for data binding, a now-withdrawn ECMAScript 7 proposal

  5. ECMAScript 5 Strict Mode

    Method of placing code in a "strict" operating context.

  6. Worker API: `Worker()` constructor: Support for ECMAScript modules

  7. ecmascript 2016 (es7)

  8. ecmascript 2017 (es8)