Mpich was developed during the MPI standards process to provide feedback to the MPI Forum on implementation and usability issues. With the release of the MPI standard, mpich was designed to provide an implementation of the MPI standard that could replace the proprietary message-passing systems on the massively parallel computers of the day, such as the Intel Paragon, IBM SP, and TMC CM5. Mpich used an early version of the abstract device interface (ADI), based on the Chameleon [14] portability system, to provide a light-weight implementation layer. To enable development on desktop systems, a device layered on top of the P4 [1] system was used. Over time, other devices were developed; as systems have vanished (e.g., the TMC CM5 and the Ncube), these devices have been dropped from our distribution. Because mpich used P4 for workstation networks, mpich has supported both MIMD programming and heterogeneous clusters from the very beginning.
Because mpich was designed to enable ports to other systems, many parallel computer vendors and research groups have used mpich as the basis for their implementation. Many users are now familar only with the version of mpich that uses the ch_p4 device for workstation and Beowulf clusters. However, mpich continues to support other systems and continues to serve as a platform for research into MPI implementations.