That depends on you. From the article: Alternatively, many ES.next features can be experimented with using Google's Traceur transpiler (useful unit tes

That depends on you. From the article: Alternatively, many ES.next features can be experimented with using Google's Traceur transpiler (useful unit tests with examples here) and there are shims available for other features via projects such as ES6-Shim and Harmony Collections.' There's also another quite comprehensive ES6 transpiler named six: https://github.com/matthewrobb/six https://github.com/matthewrobb/six