A JavaScript engine (also known as JavaScript interpreter or JavaScript implementation) is an interpreter that interpretes JavaScript source code and executes the script accordingly.

The first ever JavaScript engine was created by Brendan Eich at Netscape Communications Corporation, for the Netscape Navigator web browser. The engine, code named SpiderMonkey, is implemented in C. It has since been updated (in JavaScript 1.5) to conform to ECMA-262 Edition 3. The Rhino engine, created primarily by Norris Boyd (also at Netscape) is a JavaScript implementation in Java. Like SpiderMonkey, Rhino is ECMA-262 Edition 3 compliant.

By far, the most common host environment for JavaScript is the web browsers. Web browsers typically use the public API to create "host objects" responsible for reflecting the DOM into JavaScript.

The web servers is another common application of the engine. A JavaScript web server would expose host objects representing a HTTP request and response objects, which could then be manipulated by a JavaScript program to dynamically generate web pages.

See also

• List of JavaScript engines
• Comparison of JavaScript engines
• ECMAScript engine

External links

• JavaScript - from Mozilla Foundation