The real power of jsFiddle is that you have the option to include any of the most popular JS libraries, including; Mootools, jQuery, Prototype, YUI2.8, YUI3, Glow, Vanilla, Dojo, Processing.js, & ExtJS. This feature gives anyone the ability to try out any of these libraries without going through the task of downloading, extracting, and coded up some examples. With a few mouse-clicks you can view example snippets from any of the major JS libraries, and start editing them to see how they work.
As icing on the cake, you can take your snippets, copy the embed code, and paste them anywhere. Here’s a snippet that I was able to code up in about 15 minutes (writing this blog post took longer than that!) to demonstrate the power of YUI3, YQL, and the Twitter API. In this iframe, you’ll find all the JS, CSS, and HTML you need to create a simple little Twitter widget.
In all, this is an amazing product that I’ll likely find myself using on a daily basis.