DOS
8 operating systems
| Operating system | Developer | First release | License |
|---|---|---|---|
| Atari DOS | Atari | — | — |
| Commodore DOS | Commodore International | — | — |
| DOS Plus | Digital Research | — | — |
| IBM PC DOS | IBM | 1981 | proprietary license |
| MS-DOS | Microsoft | 1981 | MIT License, proprietary license |
| MSX-DOS | Microsoft | — | — |
| SAMDOS | Miles Gordon Technology | — | — |
| TRSDOS | Tandy Corporation | — | — |