The Message Passing Interface (MPI)  standard, whose specification was completed in April 1994, is the outcome of a community effort to try to define both the syntax and semantics of a core of message-passing library routines that would be useful to a wide range of users and efficiently implementable on a wide range of MPPs. The main advantage of establishing a message-passing standard is portability. One of the goals of developing MPI is to provide MPP vendors with a clearly defined base set of routines that they can implement efficiently or, in some cases, provide hardware support for, thereby enhancing scalability.
MPI is not intended to be a complete and self-contained software infrastructure that can be used for distributed computing. MPI does not include necessities such as process management (the ability to start tasks), (virtual) machine configuration, and support for input and output. As a result, it is anticipated that MPI will be realized as a communications interface layer that will be built upon native facilities of the underlying hardware platform, with the exception of certain data transfer operations that might be implemented at a level close to hardware. This scenario permits the provision of PVM's being ported to MPI to exploit any communication performance a vendor supplies.