If you've been itching to take advantage of the wealth of features offered by ECMAScript 6, aka JavaScript 6, but you're tired of waiting for browsers and runtime engines to get fully caught up, there's a potential solution.
6to5 is a transpiler that transforms ECMAScript 6 code into completely backward-compatible ECMAScript 5 code, with support for ES6's most notable features, including arrow notation, classes, template strings, the "let" and "const" assignment, and constructs.