I believe it is ECMAScript5 = ECMAScript2009 = Javascript5 = ES5

Babeljs.io can be used online to convert ES6 to ES5. Use the "try it out" tab.

ECMAScript6 has the confusing year 2015 name.
ECMAScript6 has "let" and (weird to me) function naming, and weird double arrows. And I think Cosh() and Sinh().

- Brian