In addition most CMSs provide basic library (source control) functionality.
The DITA focus area web site (dita.xml.org) has a list of DITA-related products, including products that provide content management functionality. See http://dita.xml.org/products-services to access the DITA product listings.
There are many web sites with information about content management. A good place to start is with CM Professionals at http://www.cmprofessionals.org.