There was an HP operating system, HP-UX that ran on all of their workstations. They even made their own line of CPUs for a while, until Microsoft and Intel gutt

There was an HP operating system, HP-UX that ran on all of their workstations. They even made their own line of CPUs for a while, until Microsoft and Intel gutted the whole RISC/UNIX workstation market by massively undercutting their prices.