- ECMAScript 5 (ES5): The 5th edition of ECMAScript, standardized in 2009. This standard has been implemented fairly completely in all modern browsers
- ECMAScript 6 (ES6)/ ECMAScript 2015 (ES2015): The 6th edition of ECMAScript, standardized in 2015. This standard has been partially implemented in most modern browsers. To see the state of implementation by different browsers and tools, check out these compatibility tables.
- ECMAScript 2016: The expected 7th edition of ECMAScript. This is scheduled to be released next summer. The details of what the spec will contain have not been finalized yet
- ECMAScript Proposals: Proposed features or syntax that are being considered for future versions of the ECMAScript standard. These move through a process of five stages: Strawman, Proposal, Draft, Candidate and Finished.
This list has been copied 1:1 from Ben McCormicks Blog post because It was just perfect as it was already 😉
¹ ECMA International was founded 1961 and stood for European Computer Manufacturers Association. In 1994 however, they got rid of the meaning and just stuck with ECMA International to underline the international importance of the organisation. They also maintain the standards for C# and other .NET components. Their headquarters are located in Geneva, Switzerland.