| 3CX Phone System | — | — | end-user license agreement |
| 86-DOS | Seattle Computer Products, Tim Paterson | 1980 | — |
| AskoziaPBX | — | — | — |
| BeOS | Be Inc., Jean-Louis Gassée, Cyril Meurillon, Jean-Baptiste Maurice Quéru, Benoit Schillings, Dominic Giampaolo, Steve Sakoman | — | proprietary license |
| DigitaOS | — | 1998 | — |
| EMUI | Huawei | — | proprietary license |
| HarmonyOS | Huawei | 2019 | — |
| NOS | Alien Internet Services | — | — |
| ONTAP | NetApp | — | — |
| OpenVMS | VMS Software Inc., Hewlett-Packard, Digital Equipment Corporation, Compaq | 1977 | proprietary license |
| PrivatOS | Silent Circle | 2014 | — |
| SabineOS | — | — | — |
| TENEX | BBN Technologies | 1969 | — |
| TOPS-20 | Leonard Bosack, Daniel Murphy, Digital Equipment Corporation | 1976 | — |
| Tru64 UNIX | Hewlett-Packard, Digital Equipment Corporation, IBM, Compaq | — | proprietary license |
| Ultrix | Digital Equipment Corporation | — | — |
| VMware ESXi | VMware | — | — |
| Windows 10 | Microsoft | 2015 | shareware, Microsoft Software Assurance, Azure Dev Tools for Teaching |
| Windows 11 | Microsoft | 2021 | end-user license agreement |
| Windows 12 | Microsoft | — | Microsoft end-user license agreement |
| Windows 2.0 | Microsoft | 1987 | proprietary license |
| Windows 2000 | Microsoft | 2000 | proprietary license |
| Windows 3.0 | Microsoft | — | proprietary license |
| Windows 3.x | Microsoft | 1990 | — |
| Windows 7 | Microsoft | 2009 | volume licensing, Microsoft Software Assurance, end-user license agreement |
| Windows 8 | Microsoft | 2012 | end-user license agreement |
| Windows 95 | Microsoft | — | proprietary license |
| Windows 95 OSR2 | Microsoft | 1996 | — |
| Windows Embedded Compact | Microsoft | — | end-user license agreement |
| Windows Me | Microsoft | 2000 | Microsoft end-user license agreement |
| Windows Mobile | Microsoft | — | proprietary license |
| Windows NT | Microsoft | 1993 | — |
| Windows NT 3.1 | Microsoft | — | Microsoft end-user license agreement |
| Windows NT 3.5 | Microsoft | — | commercial software, proprietary license |
| Windows NT 4.0 | Microsoft | — | — |
| Windows Vista | Microsoft | — | end-user license agreement |
| Windows XP Media Center Edition | Microsoft | — | — |