LAM/MPI
LAM/MPI is a high quality implementation of the MPI standard, providing complete implementation of the MPI-1.2 standard. It provides significant portions of the MPI-2 standard, including C++ bindings, dynamic process control, MPI-I/O, and one-sided communication. A daemon-based run-time environment provides fast job startup, rich debugging facilities, and guaranteed job cleanup.
Current projects include fully utilizing high-speed networks, supporting job execution environments, and incorporating resilience to failures in the run-time environment. LAM/MPI is freely available under an open source license.