As much as possible select common MPI?

[gutmann]

Cheyenne has iMPI, MPT, MPICH, OpenMPI (maybe?)

Cori will have cray MPI, anything else?

(converted to an issue to create a place for discussion)

[bcfriesen]

Cori has Cray MPI and Intel MPI. I don't think there are plans to support anything else. Cori had OpenMPI on it for a while (maybe still does), but it was difficult to use, and I never understood why anyone bothered to put it on there at all.