The CIM standard is defined and published by the Distributed Management Task Force (DMTF).
A related standard is Web-Based Enterprise Management (WBEM, also defined by DMTF) which defines a particular implementation of CIM, including protocols for discovering and accessing such CIM implementations.
There are two message types: CIM-XML forms part of the WBEM protocol family, and is standardised by the DMTF.
CIM-XML comprises three specifications: WS-MAN forms part of the WBEM protocol family, and is standardised by the DMTF.
WS-MAN comprises 3 specifications: CIM-RS forms part of the WBEM protocol family, and is standardised by the DMTF.