ECMAScript:Harmony / ES6 to JavaScript compiler

Question

After reading Peter\'s article on JavaScript I noticed

Brendan Eich stated that one the goals for Harmony is to be a better target for to-JavaScript c

Answer 1

I'm not sure in what instance compilation back to ES3 would valuable as opposed to ES5, seeing that implementation changes are limited to array and object helper functions, and ES5 support is so prevalent.

So for completeness, another ES6 to ES5 compiler is the esnext project by Square. It is a collection of a number of modules designed to polyfill various ES6 features provided in one package. Here is the list modules included: https://github.com/square/esnext#available