The rapid growth of distributed processing has lead to a need for a coordinating framework for the standardization of Open Distributed Processing (ODP). This Reference Model of ODP provides such a framework. It creates an architecture within which support of distribution, interworking, interoperability and portability can be integrated. The Basic Reference Model of Open Distributed Processing (RM-ODP), (see ITU-T Recs. X.901 to X.904 | ISO/IEC 10746), is based on precise concepts derived from current distributed processing developments and, as far as possible, on the use of formal description techniques for specification of the architecture. The RM-ODP consists of: ITU-T Rec. X.901 | ISO/IEC 10746-1: 2YHUYLHZ:_ Contains a motivational overview of ODP giving scooping, justification and explanation of key concepts, and an outline of ODP architecture. This part is not normative. ITU-T Rec. X.902 | ISO/IEC 10746-2: )RXQGDWLRQV:_ Contains the definition of the concepts and analytical framework and notation for normalized description of (arbitrary) distributed processing systems. This is only to a level of detail sufficient to support ITU-T Rec. X.903 | ISO/IEC 10746-3 and to establish requirements for new specification techniques. This part is normative. ITU-T Rec. X.903 | ISO/IEC 10746-3: $UFKLWHFWXUH: Contains_ the specification of the required characteristics that qualify distributed processing as open. These are the constraints to which ODP standards must conform. It uses the descriptive techniques from ITU-T Rec. X.902 | ISO/IEC 10746-2. This part is normative.