Ciao oha :) noösphere already does what you need:

Also important is Noosphere's support of TeX, a document authoring platform used almost universally by the professional and academic communities. LaTeX, a macro package for TeX, is a more content-semantically oriented language, and is the variant of TeX directly supported by Noosphere. The LaTeX support alone is enough of a reason for many groups to use Noosphere.

It may be simpler to start with something like this.

update: there is a problem with the link I gave but the source seems still available through CVS; search noosphere planetmath on Google and use the cached copy to read how to download code from their public CVS.