A very interesting wiki I just discovered:
http://en.literateprograms.org/LiteratePrograms:Welcome
They allow you to post source code of any computer program in any
language, comment it, etc. They have a very neat extension which
allows you to download a tarball of all the programs documented on a
particular page. The code can be broken up into pieces so that
individual sections of a program can be discussed in more detail. The
pieces on a page can then be associated with files using an internal
transclusion.
The extension pieces the stuff together again. It also does syntax
highlighting for a lot of languages.
I'm posting this to textbook-l and wikipedia-l because I know there
are a lot of computer programming related pages on both wikis that
could make use of this resource. Given the URL, the project also seems
to be aiming for multilinguality. I actually think it would make a
nice addition to the Wikimedia project family, if a bit specialized.
Erik