Document Management systems

Looking for Document Management system to replace GW

Is this a Fair analysis...

No improvements in GW8... (Sadly GroupWise is going nowhere fast specially
when it comes to DM).

Users want more functionality - access the email archiving (not the joke
archives), PDF support, Library from the Web etc.

Since we are going to have to move from Netware soon - I guess Windows is
the way to go (looking at the dead SmallBusiness Nows-SBE2 forum - Novel
doen't have a credible Small Business solution or the will power)

What other Document Management systems exist?

I've come across things like KnowledgeTree but don't have any experience of
it.

I guess others who have moved from GW DM have already left the Novell forums
but I'm looking for someone who has had to move to a better (or another)
Document Management system.