How does jsfiddle mark up code? Is there a library for this?

If you've ever used www.jsfiddle.net, you might notice that it marks up code with proper colorings, and various other helpers like translating tabs to four spaces or shift-tab. With Firebug I see that it's doing this with an iFrame. Is the开发者_如何学Gore an open source library to do this? I want to let people write Python on a web page, but make it pretty like jsfiddle.

Check out CodeMirror.

Look here (SyntaxHighlighter)

Here you can find a simple tutorial.