Widespread acceptance of the MPI standard by vendors, who are providing optimized implementations for their hardware, lead us to the conclude that the case for a high-performance compiler-oriented message-passing or data-movement interface is weaker than originally supposed. Project runtime libraries have been successfully developed on, or ported to, standard MPI. Reference [40] is a survey of the subset of MPI calls used in the various runtime components developed over the project. It suggests that there is only limited consensus amongst runtime developers on what is the most important subset of MPI. Viewed from another perspective, it suggests that the MPI standard itself is an adequate basis for runtime and compiler development.