I am looking for good backup software.  Specifically for backing up
documents, not system files.  I need it to backup on a file by file
basis, as soon as a change has been made.  It needs to keep a
predetermined number of versions of each file, and then automatically
delete the oldest versions once that number has been exceeded.  It
would also be nice if it could run on Windows 2000 Server, but that is
not required.

PowerQuest had a software product called a Datakeeper, but they only
made it available bundled with other products.  However, now
PowerQuest is owned by Symantec, and the product has no support or
upgrades.

Storactive has a product called LiveBackup. It pretty much doesw
everything you ask for.

http://www.storactive.com/solutions/liveBackup/

Also iomega offers their software Sync for free which can be used for
on-the-fly file backup. However this software is no longer supported.

http://www.iomega.com/software/sync.html

Hope these helps.

Have a look at: http://www.tech-pro.net/getback.html

LiveBackup is probably the kind of software I am looking for.  My only
aversion is that it requires 25 licenses, which brings the total cost
(including maintenance and support) to about $2,850.  Surely there is
a single computer solution that runs $450 or less.  Also, I will have
to check more into Getback, to see if it suits my needs.  Thanks.