PRRTE is the PMIx Reference Run Time Environment.
The project is formally referred to in documentation by "PRRTE", and
the GitHub repository is "openpmix/prrte".
However, we have found that most users do not like typing the two
consecutive "r"s in the name. Hence, all of the internal API symbols,
environment variables, MCA frameworks, and CLI executables all use the
abbreviated "prte" (one "r", not two) for convenience.
