This is a list of disk operating systems in which the acronym DOS is used to form their names. Many of these are simply referred to as "DOS" within their respective communities.
Other x86 disk operating systems with "DOS" in the name
86-DOS (a.k.a. QDOS, created 1980), an operating system developed by Seattle Computer Products for its 8086-based S-100 computer kit, heavily inspired by CP/M
Concurrent DOS (a.k.a. CDOS, Concurrent PC DOS and CPCDOS) (since 1983), a CP/M-86 and MS-DOS 2.11 compatible multiuser, multitasking DOS, based on Concurrent CP/M-86 developed by Digital Research
DOS Plus (since 1985), a PC DOS and CP/M-86 compatible multitasking operating system for early x86-based personal computers, based on Concurrent PC DOS 4.1/5.0 by Digital Research
Multiuser DOS (a.k.a. MDOS), a PC DOS and CP/M-86 compatible multiuser multitasking operating system based on Concurrent DOS by Digital Research
NetWare PalmDOS, a successor of DR DOS 6.0 specifically tailored for early mobile and palmtop PCs by Novell
Novell DOS, a multitasking successor of DR DOS 6.0 by Novell