The Message Passing Interface (MPI) is a language-independent computer communications descriptive application programmer interface (API), with defined semantics, and with flexible interpretations; it does not define the protocol by which these operations are to be performed in the sense of sockets for TCP/IP or other layer-4 and below models in the ISO/OSI Reference Model. It is consequently a layer-5+ type set of interfaces, although implementations can cover most layers of the reference model, with sockets+TCP/IP as a common transport used inside the implementation.

MPI's dual goals are high performance (scalability), and high portability. High productivity of the interface, in programmer terms, is not one of the key goals of MPI, and MPI is generally considered to be low-level. It expresses parallelism explicitly, rather than implicitly. MPI is considered successful in achieving high performance and high portability, but is often criticized for its low-level qualities. Nevertheless, it remains a crucial part of parallel programming to this date. MPI is not sanctioned by any major standards body, but nonetheless has worldwide practical acceptance. MPI is a de facto standard for communication among the processes modeling a parallel program on a distributed memory system. Often these programs are mapped to clusters, actual distributed memory supercomputers, and to other environments. Related Clients Cray Related Technologies Computational Fluid Dynamics Supercomputing Information Retrieval JIVA Grid Computing Framework