ES6 Shim Provides compatibility shims so that legacy JavaScript engines behave as closely as possible to ECMAScript 6 (Harmony). HTML version of the final ECMAScript 6 spec Installation If you want to use it in browser: Just include es6-shim before your scripts. Include es5-shim especially if your browser doesn't support ECMAScript 5 - but every JS engine requires the es5-shim to correct broken im