The latest version of the official specification underlying JavaScript, ECMAScript 2016, has been approved by ECMA International.
Developed under a premise of providing more frequent but smaller updates to the specification, ECMAScript 2016 has been very limited in scope. New features include an Array.Prototype.includes method, to determine if an array includes a certain element, and an exponentiation operator, for working with variables. Browser vendors like Google and Firefox have been in the habit of supporting ECMAScript specifications ahead of their official approvals anyway.