Note from THE FUTURE: there is now an Alien::OpenMP which helps writing Makefile.PL or maybe PDL .pd files. OpenMP is for shared-memory systems; MPI is a separate, complementary technology for coordinating processing between non-shared-memory systems.

There are plans https://github.com/PDLPorters/pdl/issues/349 to use OpenMP or a similar technology in PDL, though at the time of writing they are only plans.