Wiki + indexing (Score 1)

Where I work, I have set up a Wiki (MoinMoin on Python twisted webserver), and it works well. We even use it for storing files (spreadsheets, scripts etc.) by using the attachment feature. MoinMoin's search is slow, so you might need some other indexing solution. We use Microsoft Index server to index the files (our Windows file server had it installed, and it wasn't very hard to set up).