Django-RefDB is a references manager, i.e. it helps you organise
your papers and books, including PDF upload/download/OCR.
Technically, it is a Django frontend for a RefDB server.

You can install it e.g. in your research institute so that anybody
has access to all papers of everyone.  Parallely, you can set up
personal RefDB databases with documents not everybody can see.  Or,
you can use it only on your own.

BUT:

It is in alpha stage.  While I use it already productively, I've
spent last two weeks' spare time on bringing it into shape for other
developers.  So, I welcome anybody interested in converting this raw
piece of software into something really convenient and feature-rich.

The source code is well-documented, however, the peculiarity of
having almost no database models but talking to the RefDB server
instead needs getting accustomed to.

Have a look at
http://www-users.rwth-aachen.de/torsten.bronger/django-refdb.html
for more information.

Tschö,
Torsten.