CMIS is a proposed standard for improving interoperability between Enterprise Content Management (ECM) systems. It proposes a data model plus a set of generic services and several protocol bindings for these services, including: SOAP, Representational State Transfer (REST), Atom Publishing Protocol (APP or AtomPub).
Although starting as an industry initiative, CMIS is now being administered by standards body, OASIS. Participants in the process include Alfresco, Day Software, EMC, FatWire, IBM, Microsoft, Open Text, Oracle and SAP. The proposed standard is available for public comment at OASIS.