GEM serves as a graphical front end for In-situ Partial Order (ISP), a
dynamic formal verification tool for MPI developed at the School of
Computing, University of Utah.

Whether you are new to MPI or are an advanced user, GEM will help you debug
your MPI programs, and graphically show many valuable facts, including all
the possible send/receive matches, and synchronizations. GEM also includes
features to help users understand and debug the program across all platforms
on which it may be run (e.g. highlighting deadlocks that may occur due to
differing communication buffer allocations). For a given test harness, GEM
will allow you to explore only the relevant process interleavings, which are
much smaller than the number of total feasible interleavings. GEM also
guarantees to discover and explore all non-deterministic matches at run-time.