I am a member of the PediaPress team. PediaPress has the goal to increase the interoperability of wiki content with other applications.
In regard to Mediawiki the company developed:
- a full featured mediawiki-markup parser (mwlib)
- a Collection-Extension - that can be used to compile individual collection auf articles in a Mediawiki
- a PDF generator, that translates single articles or collections (see above) to PDF
- a XML representation and export of Mediawiki articles
- an OpenDocument export of single articles or collections (see above)