The language is actually called ECMAScript. It's in its 5th version right now. As its name suggests, it is standardized by ECMA.<p>JavaScript is a name that is licensed to Mozilla by Sun Microsystems. Technically speaking, only Mozilla can use the name "JavaScript". The Microsoft version used to be called JScript. The Adobe version is called ActionScript (ActionScript eventually turned out to be its own sorta language that vaguely conforms to ES standards).<p>Because ECMAScript is just a specification, it is up to the implementors to conform or not to the spec. Mozilla itself does a lot of weird stuff that doesn't actually conform to the spec. But for the main uses, all three major engines(V8, Spidermonkey and Chakra) are all pretty okay.<p>If you learn JS for use in node.js, then you are mainly learning the quirks of V8's implementation (of which thankfully are minimal). You may think that V8/Chrome is the dominant JS engine out there, but there are some softwares like CouchDB which uses SpiderMonkey as its engine.<p>In the past, I believe there used to be a mini language out of Java, also called Java Script, but that quickly fell out of use.<p>JavaScript as a language was designed to look similar to Java, to catch on the Java-is-the-best-thing-since-sliced-bread bandwagon in the early 1990s. Of course, when you mix paradigms, you have weird shit like ASI in JavaScript.<p>source: I am writing a couple of books about JavaScript.