[UFO Chicago] Looking for a simple document management system

[Christopher D. Heer]

Hey folks.

I'm looking for a simple document management system (open source) to run 
on a Debian/Ubuntu box for my son's small office:

* Browser-based on the client side
* Allows adding/listing/browsing/searching for files
* Allows categorization along various lines (clients, file types, etc.)
* Allows fine-grain access controls (by user or group -- no access, read 
access, write access, etc.)
* Logs all file accesses

Ideally it would also have some kind of check-in/check-out system and 
revision tracking, but that's not as critical.  So far everything I've 
looked at is either massively complicated (e.g. Nuxeo) or are too simple 
(OpenDocMan).

I'll keep poring over what I can find, but I was curious if anybody here 
had any familiarity with packages like this.

Thanks!

--chris