It's a pity it's "open source" and not free software including Emacs, in particular, which has been rather successful itself and as a model long-term. I wonder

It's a pity it's "open source" and not free software including Emacs, in particular, which has been rather successful itself and as a model long-term. I wonder how some of these architectures have really helped with maintenance. For instance, I'm familiar with Open MPI and its rather sorry maintenance history with continual breakage and at least partially unnecessary lack of compatibility. Then it still seems the best bet for general purpose MPI...