This report presents the architecture, services and performance results obtained from the implementation of the PVM parallel processing tool supported by either the Unix operating system and the RHODOS distributed operating system. It is shown that the provision of several advanced services in RHODOS allow the implementation of PVM to be greatly simplified, and significant speed-ups to applications can be achieved. These services allow the dynamic establishment of a virtual machine by removing heavily loaded and adding idle/lightly loaded workstations, place processes on workstations to optimise static allocation, instantiate processes using group process creation and balance load dynamically using process migration. The performance study shows that the processing time of PVM applications executed on the RHODOS virtual machine is much shorter than those achieved on the Unix virtual machine.