This is pretty much the idea I had about replacing MPI for my HPC projects - I'll certainly check this out once I have python bindings for my Fortran code (yes I'm serious ;-) ). Are there any benchmarks available that compare this to pure Fortran+MPI or C/C++ + MPI (with the lsci version using wrapped versions of the same code)? I think this could have great benefits for stability regarding Erlang's respawning of processes if you implement proper checkpointing facilities that can be passed through to the python code as well as C/Fortran code wrapped with python. Stability is the big thing to solve for Exascale applications - but performance kind of needs to be proven first when it comes to HPC.