PVM is mainly a simulation of a computer machine running parallel programs. It is a software package that allows a heterogeneous collection of UNIX and/or Windows computers hooked together by a network to be used as a one large parallel computer. It contains a combination of good features of several operating systems and architectures. Therefore large computational problems can be solved more cost effectively by using the combined power and memory of many computers. The software is extremely portable. The source, which is available free by netlib, has been compiled on a range of computing machines from laptops to CRAY machines.
PVM allows users to exploit their existing computer hardware to explain much larger problems at minimal additional cost. Hundreds of sites around the globe are using PVM to solve industrial, important scientific and medical problems. Further, PVM's are being used as educational tools to teach parallel programming. With tens of thousands of users, PVM has started the de facto standard for distributed computing world-wide.