Fortran and C
include mpif.h
Call MPI_xxx(…,ierr)
Case insensitive
Array storage column
major
a(1,1),a(2,1),a(3,1)…
contiguous
#include mpi.h
rc = mpi_xxx(….)
    rc = MPI_SUCCESS
Case sensitive
Array storage row
major
a(1,1),a(1,2),a(1,3)…
contiguous