Yes, "HPC workload-scheduling software with multi-tenant customer usage accounting" does cost a hundred million dollars to develop and takes 5–10 years to build.

But some research labs (Lawrence Livermore National Laboratory, the research arm of HP, and a few others) got together to build it ~2002, and decided to make the results open source.

And that's what SLURM is. No, really.

> Slurm is the workload manager on about 60% of the TOP500 supercomputers.