PVMPI is a research project based at Oak Ridge National Laboratory and the University of Tennessee at Knoxville whose goal is to allow MPI implementations from different vendors to interoperate. It is advertised that the application programmer uses MPI for communication between all processes, plus a few PVMPI routines for establishing communication between MPI implementations -- PVMPI was designed before MPI-2 was finalized. Internally, PVMPI uses PVM for communication between processes tied to the different implementations, and native MPI (through the MPI profiling interface) for communication among processes associated with a single MPI implementation. As of this writing, the software is not yet available, and it is not clear how many MPI details can be relied on. Based on available information, it seems that PVMPI will be a good starting point for a full meta-MPI implementation, and a good way for applications that need interoperability now and cannot wait for such an implementation, but that PVMPI will not provide full MPI interoperability, and will be missing many MPI features. For more information, see http://www.netlib.org/mpi/pvmpi/pvmpi.html.