PVM (Parallel Virtual Machine) is a portable message-passing programming
system, designed to link separate host machines to form a ``virtual
machine'' which is a single, manageable computing resource.

The virtual machine can be composed of hosts of varying types, in
physically remote locations. PVM applications can be composed of any
number of separate processes, or components, written in a mixture of C,
C++ and Fortran. The system is portable to a wide variety of
architectures, including workstations, multiprocessors, supercomputers and
PCs.

PVM is a byproduct of ongoing research at several institutions, and is
made available to the public free of charge.

Homepage:
https://www.csm.ornl.gov/pvm/pvm_home.html
