Everyone needs a good syntax highlighter on their blog, and this one’s pure Javascript. Because people that post code are cool

dp.SyntaxHighlighter - free JavaScript syntax highlighting

dp.SyntaxHighlighter is a free JavaScript tool for source code syntax highlighting.
The script is meant to help a developer to post code snippets online with ease and without having to worry about applying format. People who use blogs like MovableType, .Text (dotText), dasBlog and any other system can easily add code to their posts.