| /e/OS | Gaël Duval, E Foundation | 2018 |
| 9front | — | — |
| Alpine Linux | — | — |
| Amoeba | Andrew S. Tanenbaum | — |
| ArkOS | — | — |
| Athena OS | — | — |
| Axle OS | — | — |
| Azure Linux | Microsoft | — |
| Azure Sphere OS | Microsoft | — |
| Barrelfish | — | — |
| Essence | Nakst | — |
| Fedora Linux | Red Hat, IBM, Fedora Project | 2003 |
| FreeRTOS | — | 2003 |
| Fuchsia | Google | — |
| GrapheneOS | Daniel Micay | 2016 |
| Haiku | Michael Phipps, Haiku Inc. | 2002 |
| Inferno | Vita Nuova Holdings, Bell Labs | — |
| Jehanne | — | — |
| KnightOS | — | — |
| Lilith | — | — |
| Mezzano | — | — |
| MoKee ROM | — | 2012 |
| MonaOS | — | — |
| MS-DOS | Microsoft | 1981 |
| MS-DOS 1.25 | Microsoft | 1982 |
| MS-DOS 2.0 | Microsoft | 1983 |
| MS-DOS 4.0 | Microsoft | 1988 |
| Multi-tasking MS-DOS 4.0 | Microsoft | 1986 |
| Multics | Bell Labs, Massachusetts Institute of Technology, General Electric | 1969 |
| NixOS | Thomas Tuegel, Eelco Dolstra | — |
| NodeOS | — | — |
| Omarchy | David Heinemeier Hansson | — |
| OpenIPC | Igor Zalatov | — |
| OreoOS | — | — |
| Plan 9 | Bell Labs | 1992 |
| R9 | — | — |
| Redox | Jeremy Soller | — |
| SkiftOS | — | — |
| Sprite | University of California, Berkeley | — |
| Theseus | — | — |
| ThreadX | — | — |
| Tock | Brad Campbell, Amit Levy | — |
| VibeOS | — | 2025 |
| Xv6 | Massachusetts Institute of Technology | — |