Also known as EcmaScript 2016

• Babel - Turn ES6+ code into vanilla ES5 with no runtime
• Traceur compiler - ES6+ features > ES5. Includes classes, generators, promises, destructuring patterns, default parameters & more.

• Babel: grunt-babel - Turn ES6+ code into vanilla ES5 with no runtime
• Traceur: grunt-traceur ES6+ > ES5 transpilation, grunt-traceur-build

• Babel: gulp-babel
• Traceur: gulp-traceur

• Babel: broccoli-babel-transpiler
• Traceur: broccoli-traceur

• Babel: babel-brunch

• Babel: babel-loader
• Traceur: traceur-compiler-loader

• Babel: duo-babel

• Babel: babel-connect

• Babel: gobble-babel
• Traceur: gobble-es6-transpiler

• Babel: jade-babel
• Traceur: jade-traceur

• Babel: babel-jest

• Babel: karma-babel-preprocessor
• Traceur: karma-traceur-preprocessor

• Babel: sprockets-es6
• Traceur: sprockets-traceur

• Scratch JS - A Chrome/Opera DevTools extension to run ES7 on a page with either Babel or Traceur

• core-js - Modular and compact polyfills for ES6 including Symbols, Map, Set, Iterators, Promises, setImmediate, Array generics, etc. The standard library used by Babel.
• es7-shim - ECMAScript 7 compatibility shims for legacy JavaScript engines

• ES6 syntax highlighting for Sublime Text and TextMate
• ES6 syntax support in WebStorm and PhpStorm, compilation to ES5 with Traceur file watcher
• DocPad plugin for Traceur

• Esprima Harmony branch - Experimental branch of the Esprima parser which can parse ES6 features to SpiderMonkey AST format.
• Acorn - A small, fast, JavaScript-based JavaScript parser with ES6 support, parses to SpiderMonkey AST format.
• esparse - ES6 parser written in ES6.
• Traceur compiler also has built-in parser available under traceur.syntax.Parser.