| Bullx SCS | Atos SE | — | — |
| Cray Operating System | Cray | — | — |
| Cray Time Sharing System | Lawrence Livermore National Laboratory, Los Alamos National Laboratory | — | — |
| EOS | ETA Systems | — | — |
| HPE Cray Operating System | — | — | — |
| INK | — | — | — |
| Livermore Time Sharing System | Lawrence Livermore National Laboratory | — | — |
| Multiple Console Time Sharing System | General Motors Research Laboratories | — | — |
| NLTSS | Lawrence Livermore National Laboratory | — | — |
| SUPER-UX | NEC | — | — |
| UNICOS | Cray | — | — |