I read a thread that recommended incorporating GeSHi for generic syntax highlighting.
I added code that uses GeSHi and an admin page. The admin page lets the user enable/disable geshi, set the page to geshi and set a default language. There is also support code that allows the user to adjust the language on the fly by addin it to the code tag, like this
I basically left all the existing codefilter code alone so if geshi is disabled it should bahave just as it used to.