SyntaxHighlighter
Wyatt's Blog is now using SyntaxHighligher from Google Code
var thing = document.createElement('div'); thing.classname = "asdf"; alert(thing.classname); for(var i = 0; i < 10; i++) { alert('hello'); }
UPDATE - 2011-11-19:
Some time ago Alex Gorbatchev moved SyntaxHighlighter from Google Code to its own site - http://alexgorbatchev.com/SyntaxHighlighter - this is the URL you want to use.