There's a project out there for those that might need a bit more to their syntax highlighting than the standard PHP functionality might allow. Enter GeSHi, the Generic Syntax Highlighter - and it's latest snapshot on it's development track to version 1.1.1.
GeSHi supports PHP5 and Windows, and has even been used to highlight code on ASP pages. Numerous blogs, wikis and forums use GeSHi, including Dokuwiki, Mambo, phpBB and WikkiWiki.
From the development branch comes another snapshot on the way to 1.1.1. This one adds beginning support for VHDL, courtesy of Lingzi Xue and Java, thanks to Tim Wright.
GeSHi started as an idea to create a generic syntax highlighter for the phpBB forum system, but has been generalised to this project. GeSHi aims to be a simple but powerful highlighting class.
You can check out the complete specs of the software here, or just download it and give it a try...