The history of JavaScript is a bit convoluted. It was first released as LiveScript by Netscape, but was later renamed to JavaScript in the December 1995 release of the Netscape Navigator 2.0B3 browser, which also had support for Java applets. This is thought to have been a deciding factor for the name change.
Unfortunately, JavaScript and Java have very little in common, and the name has led to quite a lot of confusion over the years. JavaScript 1.1 was standardized by the European Computer Manufacturers Association (ECMA) (see http://www.ecma-international.org/memento/index.html).
Microsoft has created its own variant of JavaScript called JScript. JavaScript 1.5 and JScript 5.5 are conformant with ECMAScript version 3.
For more information about the history of JavaScript, see the wiki page at http://en.wikipedia.org/wiki/JavaScript.
It was actually used on the server in one of its earliest incantations by Netscape, but server-side JavaScript has...