Proprietary operating systems

MenuetOS is an operating system with a monolithic preemptive, real-time kernel, including video drivers, all written in FASM assembly language, for 64-bit and 32-bit x86 architecture computers, by Ville M.

Windows 10 is a personal computer operating system developed and released by Microsoft as part of the Windows NT family of operating systems.

Integrity and Integrity-178B are real-time operating systems (RTOSes) produced and marketed by Green Hills Software.

Cisco IOS (originally Internetwork Operating System) is a family of software used on most Cisco Systems routers and current Cisco network switches.

DR-DOS (DR DOS, without hyphen up to and including v6.0) is an operating system of the DOS family, written for IBM PC-compatible personal computers.

86-DOS is a discontinued operating system developed and marketed by Seattle Computer Products (SCP) for its Intel 8086-based computer kit.

OpenServer, previously SCO UNIX and SCO Open Desktop (SCO ODT), is a closed source computer operating system developed by Santa Cruz Operation (SCO), later acquired by SCO Group, and now owned by Xinuos.

Nucleus RTOS is a real-time operating system (RTOS) offered by the Embedded Software Division of Mentor Graphics for various central processing unit (CPU) platforms.

SkyOS (Sky Operating System) was a prototype commercial, proprietary, graphical desktop operating system written for the x86 computer architecture.

OS-9 is a family of real-time, process-based, multitasking, multi-user operating systems, developed in the 1980s, originally by Microware Systems Corporation for the Motorola 6809 microprocessor.

Sailfish OS (also styled as SailfishOS or abbreviated to SFOS) is a mobile operating system combining the Linux kernel for a particular hardware platform use, the open-source Mer core middleware, a proprietary UI contributed by Jolla, and other third-party components.

z/OS is a 64-bit operating system for IBM mainframes, produced by IBM.

Pilot was a single-user, multitasking operating system designed by Xerox PARC in early 1977.

Spring is a discontinued project/experimental microkernel-based object oriented operating system developed at Sun Microsystems in the early 1990s.

VME (Virtual Machine Environment) is a mainframe operating system developed by the UK company International Computers Limited (ICL, now part of the Fujitsu group).

GEOS (Graphic Environment Operating System) is a discontinued operating system from Berkeley Softworks (later GeoWorks).

NeXTSTEP is a discontinued object-oriented, multitasking operating system based on UNIX.

IBM PC DOS (an acronym for IBM personal computer disk operating system) is a discontinued operating system for the IBM Personal Computer, manufactured and sold by IBM from the 1981 into the 2000s.

magnussoft ZETA, earlier yellowTAB ZETA, was an operating system formerly developed by yellowTAB of Germany based on the Be Operating System developed by Be Inc.

QNX (/ˌkjuː ˌɛn ˈɛks/ or /ˈkjuːnᵻks/) is a commercial Unix-like real-time operating system, aimed primarily at the embedded systems market.

MDOS (short for Myarc Disk Operating System) is an operating system commercialized by Myarc.

Multiuser DOS is a real-time multi-user multi-tasking operating system for IBM PC-compatible microcomputers.

The Multiple Console Time Sharing System (MCTS) was an operating system developed by General Motors Research Laboratory in the 1970s for the Control Data Corporation STAR-100 supercomputer.

PrivatOS was an operating system used in the Blackphone from June 1, 2014, to June 30, 2016.

CP-6 is a discontinued computer operating system developed by Honeywell, Inc.

LOCUS was a distributed operating system developed at UCLA during the 1980s.

S-Net was a network operating system and the set of network protocols it used to talk to client machines on the network.

The OASIS operating system (renamed THEOS in about 1983) was originally developed and distributed in 1977 by Phase One Systems of Oakland, California (President Howard Sidorsky).

OS4000 is a proprietary operating system introduced by GEC Computers Limited in 1977 as the successor to GEC DOS, for its range of GEC 4000 series 16-bit, and later 32-bit, minicomputers.

XOS was an operating system for the XDS Sigma series of computers "optimized for direct replacement of IBM DOS/360 installations" and to provide real-time and timesharing support.

The MCP (Master Control Program) is the proprietary operating system of the Burroughs small, medium and large systems, including the Unisys Clearpath/MCP systems.

(This article is about the operating system. For the SEPTA station, see Primos (SEPTA station).) PRIMOS is a discontinued operating system developed during the 1970s by Prime Computer for its minicomputer systems.

Time Sharing Operating System, or TSOS, was an operating system for RCA mainframe computers of the Spectra 70 series.

NonStop OS is an operating system developed by HP for their NonStop series of servers.

MS-DOS (/ˌɛmɛsˈdɒs/ EM-es-DOSS; acronym for Microsoft Disk Operating System) is a discontinued operating system for x86-based personal computers mostly developed by Microsoft.

DX10 was a general purpose, multitasking operating system designed to operatewith the Texas Instruments 990/10, 990/10A and 990/12 minicomputers using thememory mapping feature.

Stratus VOS (Virtual Operating System) is a proprietary operating system running on Stratus Technologies fault-tolerant computer systems.

GEOS is a computer operating environment, graphical user interface, and suite of application software.

Versatile Real-Time Executive (VRTX) is a real-time operating system developed and marketed by the company Mentor Graphics.

BS2000 (renamed BS2000/OSD in 1992) is a mainframe computer operating system developed in the 1970s by Siemens (Data Processing Department EDV) and from early 2000s onward by Fujitsu Technology Solutions.

The Pick operating system (often called just "the Pick system" or simply "Pick") is a demand-paged, multiuser, virtual memory, time-sharing computer operating system based around a unique MultiValue database.

68K/OS was a computer operating system developed by GST Computer Systems for the Sinclair QL microcomputer.

System 6 (also referred to as System Software 6) is a graphical user interface-based operating system for Macintosh computers.

EOS was the discontinued operating system developed by ETA Systems (a spin-off division of Control Data Corporation) for use in their ETA10 line of supercomputers in the 1980s.

The Business Operating System, or BOS, was initially developed as an early cross-platform operating system, originally produced for Intel 8080 and Motorola 6800 computers, then redeveloped for actual businesses and business models.

The Cray Time Sharing System, also known in the Cray user community as CTSS, was developed as an operating system for the Cray-1 or Cray X-MP line of supercomputers.

The Operating System Embedded (known by the acronym Enea OSE) is a real-time embedded operating system created by the Swedish information technology company ENEA AB.