highlight.js (softwaremaniacs.org)

highlight.js highlights syntax in code examples on blogs, forums and in fact on any web pages. It's very easy to use because it works automatically: finds blocks of code, detects a language, highlights it.
This is not only convenient but also allows highlighting for code examples marked up with writing syntaxes like Markdown where there is no way to specify HTML class easily.
The program knows following languages:
Python Ruby Perl PHP XML HTML CSS Django Javascript BScript Delphi Java C++ RenderMan (RSL and RIB) SQL SmallTalk Axapta 1C Ini Diff DOS .bat Bash

Download version 4.1

Demo