A plugin to easily present source code on your site with syntax highlighting and formatting (as seen in code editors, IDEs).
iG:Syntax Hiliter allows you to post source code to your site with syntax highlighting and formatting (as seen in code editors, IDEs). You can paste the code as is from your code editor or IDE and this plugin will take care of all the code colouring and preserve your formatting. It uses the GeSHi library to colourize your code and supports over a 100 programming languages. Most common languages are included with the plugin and it includes drop in support for more languages used by GeSHi.
WordPress.org plugin repo: http://plugins.svn.wordpress.org/igsyntax-hiliter/