I did a Document Management project on my current jobsite. There was not a budget for the big, dedicated tools out there. We had to come up with something clever. After a bit of research, I recommended Microsoft Visual Sourcesafe as the tool for our "Document Control System." Sourcesafe was already in place on many machines (especially the developers'), and the license was in-place.
The end-users have been quite impressed and very happy across a broad spectrum of end-user (QA, Product Development...hey, we even use it in Documentation!)
We created a document management database on a dedicated server that we back up nightly. And you can enact a very strict security scheme (passwords, foldered departments can only access their own files, etc). Used with an intranet and it becomes a powerful tool.
I can give you more details if you want to respond offline.
Technical Writer, NYC
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