Hey,
I'm looking for some sort of CMS system to implement here in terms of "documentation" system.
Now, I'm not to sure about which system(s) would suit my needs best, so I thought I'd come here and type up my requirements so you could help me in narrowing down all the different options.
One important note to make is that I'm not looking at a system where I can store certain documents (word, pdf, whatever). Rather at a system where I can type the "documentation"-text in some sort of post (like a blog).

Requirements:
- Multilanguage support
- Tagging
- Decent search support (tags, groupings, categories)
- Version-control of posts/articles
- Possibility of exporting post(s) to a pdf file
- Support for multi-user (usergroup X can only see those posts, usergroup Y can see others, etc...)

I know, these are some strange requirements if they're all combined, and I reckon most of you would perhaps say that I'd have to develop something like this inhouse rather then finding a descent working product out there (open source if possible).
None the less, I thought I'd at least ask the opinion of y'all.

Regards,
Tim