sourcehighlight is annoyingly slow, but it does support wiki directives 
in comments. See [here](http://www.cs.unb.ca/~bremner/teaching/java_examples/snippet/ListMerge/)
for an example (tags).

* * * * *

I think having the option to choose source code page types from the
dropdown list is definitely a feature.  This gives users an easy way
to contribute programs (say `.pl` files) or code snippets (like, for
example, the Elisp area of the EmacsWiki).  Actually, would there any
other way to create a `.pl` file without write access to the
repository?  --[[JasonBlevins]]