Optaros has followed up their fairly recent open source WCM white paper with an overview of the leading open source document management solutions called, “Unleashing the Power of Open Source in Document Management”.
The paper puts Alfresco in the “magic quadrant” with the highest enterprise readiness and application capabilities. Plone is given a close second but has a much larger and more active community.
People new to document management but not necessarily considering open source might still want to take a look at this. Almost half of the paper is on general document management.