# List of disk operating systems called DOS

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.

## MS-DOS / IBM PC DOS compatible systems

* MS-DOS (since 1981), Microsoft operating system based on 86-DOS for x86-based personal computers
* IBM PC DOS (since 1981), rebranded OEM version of MS-DOS sold by IBM. Identical or almost identical to MS-DOS until PC DOS version 6
* DR-DOS (since 1988), MS-DOS-compatible operating system originally developed by Digital Research
* ROM-DOS (1989), MS-DOS clone by Datalight
* PTS-DOS (since 1993), MS-DOS clone developed in Russia by PhysTechSoft
* FreeDOS (since 1998), open source MS-DOS clone

## 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
* OpenDOS, a successor of Novell DOS by Caldera

## Disk operating systems for the Atari 8-bit family

* Atari DOS, from Atari, Inc.
* DOS XL, from Optimized Systems Software
* MyDOS
* SmartDOS
* SpartaDOS
* SpartaDOS X
* TOP-DOS
* Turbo-DOS

## Disk operating systems for other platforms

* AmigaDOS, disk operating system portion of AmigaOS
* AMSDOS, for Amstrad CPC compatibles
* ANDOS, operating system for the Russian Electronika BK
* Apple DOS, operating system for the Apple II series from late 1978 through early 1983
* Apple ProDOS, name for both ProDOS 8 for the Apple II and ProDOS 16 for the Apple IIGS
* Commodore DOS, for Commodore's 8-bit computers
* Cromemco DOS (CDOS), a CP/M-like operating system
* CSI-DOS, for the Soviet Elektronika BK computers
* DOS (Diskette Operating System), a small OS for 16-bit Data General Nova computers, a cut-down version of their RDOS.
* DEC BATCH-11/DOS-11, the first operating system to run on the PDP-11 minicomputer
* Delta DOS, third party option from Premier Microsystems for the Dragon 32/64
* DIP DOS, the operating system of the Atari Portfolio
* DOS/360, 1966 IBM System/360 mainframe computer Disk Operating System
* DragonDOS, for the Dragon 32/64
* GEMDOS, one of the components of Atari TOS
* IDOS, for the Ivel Ultra Apple II clone
* IS-DOS, for Russian ZX Spectrum clones, developed in 1990 or 1991
* IMDOS, for IMSAI 8080
* MasterDOS, replacement DOS for the SAM Coupé
* MDOS (Micropolis DOS) for S-100
* MDOS, Myarc Disk Operating System for the Geneve 9640
* MSX-DOS, a cross between MS-DOS 1.0 and CP/M developed by Microsoft for the MSX computer standard
* NewDos/80, third-party option for the TRS-80
* Oric DOS, for the Oric-1 home computer
* PTDOS, for the 1970s Sol-20 from Processor Technology
* SAMDOS, original DOS for the SAM Coupé
* SDOS, for the SWTPC 6800 from the Southwest Technical Products Corporation
* Sinclair QDOS, for the Sinclair QL
* RDOS, a real-time operating system released in 1972 for the Data General Nova and Eclipse minicomputers
* SK*DOS, for Motorola 68000-based systems
* TR-DOS, for the ZX Spectrum
* TRSDOS, for the Tandy TRS-80 line of 8-bit Zilog Z80 microcomputers
* Xtal DOS for the Tatung Einstein