Are you speaking of large numa machines like the old SGI Origin machines where a single OS image ran on thousands of CPUs distributed along multiple racks or a

Are you speaking of large numa machines like the old SGI Origin machines where a single OS image ran on thousands of CPUs distributed along multiple racks or a grid or cluster of smaller general purpose machines like the classic Linux Beowulf cluster? Both very different but have the same goal. Plan 9 is very close. Its kernel was designed from the start with multi-processing and is all channels internally. It's small and highly portable so it runs on a Rpi and there was an IBM Blue Gene project. It's architecture is distributed so one machine can serve disk and auth and a hundred more can boot and auth to them. Then they can share resources seamlessly as everything happens through the foundational 9P protocol. There was never a framework or API to fully abstract this for HPC but could be implemented with minimal effort as the foundation is there (e.g. You wouldn't need mpi as you have 9p.) Though general work loads can be pushed to CPU servers using ssh like commands to do thin me line run programs in pipes across machines.