Run JavaScript, CSS and HTML code online using jsfiddle.net

We can run JavaScript, CSS and HTML online on website:
http://jsfiddle.net/
In this website, the top left column is HTML code, right column CSS code, bottom left javaScript code. After clicking Run, the result will be shown in the right bottom.
In the left menu of Framework and extensions, we can select different JavaScipt libraries:
Mootools, jQuery, Prototype, YUI, Glow, Dojo, Processing.js, ExtJS, Raphael,  Right.JS, three.js, Zepto, Enyo, shipyear, knockout.JS,  The X Toolkit, AngulatJS, Ember and much more.