Content Management Interoperability Services (CMIS) is an open source OASIS standard that enables applications to work with one or more content management systems. CMIS defines a standard domain model and standard set of services and protocol bindings for web services and RESTful AtomPub.
The OASIS CMIS Technical Committee maintains a website that includes information about various implementations of CMIS at http://www.oasis-open.org/committees/tc_home.php?wg_abbrev=cmis.
IBM® maintains a page for CMISInformation Management software, which includes links to developerWorks® topics and other useful resources, at http://www.ibm.com/software/data/content-management/cm-interoperablity-services.html.