Early machine capable of distributing computing.

Lincoln Lab, USA

Early machine capable of distributing computing.

National Bureau of Standards, USA

Early operating system.

IBM, USA

Very early operating system developed by General Motors for the IBM 701. Unnamed.

General Motors, USA

Operating system developed for its Whirlwind computer. Also used for the UNIVAC 1103. The first example of a Job Control Language (JCL) driven operating system.

MIT, USA

The General Motors Research Laboratories implemented an operating system for the IBM 701. Generally considered the first operating system.

General Motors, USA

Based on General Motors Operating System.

General Motors, USA

Very early operating system developed by General Motors and North American Aviation for the IBM-704.

General Motors and North American Aviation, USA

Early computing environment originally implemented as a batch processing operating system at Bell Labs for the IBM 704 computer.

IBM, USA

University of Michigan Executive System. Batch operating system.

IBM, USA

FORTRAN Monitor system.

North American Aviation, USA

Semi-Automatic Ground Environment system. Control Program for IBM AN/FSQ7 to monitor weapons systems. First real-time control system.

IBM, USA

SHARE Operating System. Improvement on the General Motors GM-NAA I/O operating system, the first operating system.

SHARE user group, USA

Semi-Automatic Business Related Environment. The first major transaction processing system, developed by IBM and American Airlines for the IBM 7090.

IBM, USA

Disk Operating System for RCA Spectra 70 series.

USA

Unix-like OS for IBM System/360 and sucessors.

IBM, USA

Operating system for IBM mainframes.

IBM, USA

Basic Programming Support. Business-oriented OS for the IBM/360.

IBM, USA

Batch Time-Sharing Monitor for XDS Sigma 5/7.

USA

Research OS for the CDC 6400.

USA

Master OS for Varian minicomputers. Tape or disk based batch system.

USA

Mobile Operating System. Soviet RIAD mainframes operating system.

Russia

Honeywell Executive System. Operating System for the Honeywell 800.

Honeywell, USA

Virtual machine system for the Hitac 8400 (RCA Spectra 70/45).

Hitachi, Japan

Advanced Monitor System. A single user interactive disk or tape OS for the PDP-9 & PDP-15.

DEC, USA

Operating system for the IBM 1410/1710.

IBM, USA

Operating system for ES EVM.

Russia

Bootable serial I/O monitor for loading programs.

IBM, USA

Early OS for DEC minicomputers.

USA

Mansfield and Cahlander Executive. SCOPE competing operating system. Original name for CDC KRONOS OS.

Control Data, USA

Input Output Control System. An early I/O Executive for the IBM 7090.

IBM, USA

First Soviet operating system.

Russia

Real-time disk operating system for the IBM 1710.

USA

J variant that allowed interactive access.

International Computers Limited, UK

Direct Access Programming System.

Bull-General Electric, USA

Operating System for NCR Century series computers.

NCR, USA

Operating System for NCR Century series computers.

NCR, USA

Operating System for NCR Century series computers.

NCR, USA

Operating System for NCR Century series computers.

NCR, USA

Memory-based real-time executive for the IBM 1710.

IBM, USA

System 4 operating system.

ICL, UK

Real-Time Multiprogramming Operating System. 24-bit process control operating system that supported both real-time computing and multiprogramming.

General Electric, USA

JOHNNIAC Open Shop System. An early on-line computing system for the JOHNNIAC computer.

Rand, USA

Disk Monitor System. Single-task batch-oriented system.

IBM, USA

Primary Control Program, very early version of OS/360 that didn't support multiprogramming.

IBM, USA

CDC operating system, descendent of Chippewa.

Control Data, USA

Proprietary operating system of the Burroughs small, medium and large systems, including the Unisys Clearpath/MCP systems.

Burroughs, Unisys, USA

Master Control Program. Proprietary operating system of the Burroughs small, medium and large systems, including the Unisys Clearpath/MCP systems.

Unisys, USA

Compatible Time-Sharing System. Developed at MIT's Computation Center for use on a modified IBM 7094.

MIT, USA

Honeywell, USA

Operating system for GE computers.

General Electric, USA

General Comprehensive Operating System. Originally GECOS, General Electric Comprehensive Operating Supervisor.

General Electric, USA

Operating system for the CDC 1604 computer.

Control Data, USA

Tape based operating system for IBM 7090 and IBM 7094.

IBM, USA

Burroughs, USA

UNIVAC's original operating system developed for the UNIVAC 1107.

UNIVAC, Unisys, USA

Operating system for the Bendix G-20 computer.

Bendix, USA

Supervisor Program for the first computer designed to use an operating system. Introduced system calls and virtual storage. Multiprogramming OS.

Manchester University, UK

Master Control Program.

Burroughs, USA

Operating system for the Philco-2000 computer.

Philco, USA

Batch-oriented operating system for the Philco-2000 computer.

Philco, USA

ADMIRAL Master Monitor. Operating system for the Honeywell 800/1800.

Honeywell, USA

Operating system for the CSIRONET ?

CSIRO, Australia

Burroughs Master Control Program. Proprietary operating system of the Burroughs small, medium and large systems, including the Unisys Clearpath/MCP systems.

Burroughs, USA

Early time-sharing system.

Queen's University of Belfast, UK

Series of operating systems for the NEAC-series 2200, which was developed in technical collaboration with Honeywell.

NEC, Honeywell, Japan

Supervisory Control Of Program Execution or Simultaneous Control Of Program Execution. File-oriented system using mass storage, random access devices. Productized version of Chippewa.

Control Data, USA

General Electric Comprehensive Operating System.

General Electric, USA

Supervisory Control Program.

GEC Computers, USA

Time Sharing Monitor. Early timesharing OS for the 7090.

IBM, USA

Operating system for the SDS 9000 computer.

Scientific Data Systems, USA

Early timesharing system for the AN/FSQ-32.

USA

Dartmouth Time-Sharing System. Timesharing with the BASIC language for liberal arts students, on a novel 2-computer system (GE-235 + Datanet 30).

Dartmouth College, USA

Comprehensive Operating Supervisor.

General Electric, USA

Operating system for the RCA 3301 computer.

RCA, USA

Multiprogramming operating system.

Burroughs, USA

Operating system for Scientific Data Systems' SDS 940.

Scientific Data Systems, USA

Timesharing/Total Operating System-10. Discontinued operating system from DEC for the PDP-10 (or DECsystem-10) computer family.

DEC, USA

Tape OS.

Hitachi, Japan

Tape Operating System. Early operating system for the RCA Spectra 70.

USA

IBM's Tape Operating System. Similar to BOS above and more fleeting, able to boot and run from 2x00 series tape drives.

IBM, USA

Often licensed and renamed. Business-oriented OS featuring an integral relational database.

Prime Computer, Pick Systems, USA

Time Sharing Operating System. First OS supporting virtual addressing of the main storage and support for both timeshare and batch interface. Renamed VMOS.

RCA, USA

Operating system for the SDS Sigma 7 real-time data processing computer.

USA

Operating system for the CDC 6600 supercomputer. Original name of SCOPE.

Control Data, USA

Simultaneous Processing Operating System.

Control Data, USA

Primary OS.

Hitachi, Japan

Operating system for the IBM 1130.

IBM, USA

Operating system for TOSBAC-5100/10. Was capable of continuously executing batch jobs using a magnetic tape.

Toshiba, Japan

Multiplexed Information and Computing Service. Operating system (written in PL/I) whose design began in the late 60's, co-written by MIT, AT&T Bell Labs and GE, that was meant to become the be-all-end-all of OS technology by having just every (un)imaginable feature, and that was supplanted by Unix, despite the fact that Multics was much better(?) designed, because Unix' simple and stubborn design was much more adapted to the very resource-poor architectures of the time. Originally developped for the GE-645 and later the Honeywell 6180.

MIT, GE, Bell Labs, USA

An IO Control System for the DDP-116 minicomputer. One of the earliest OSs for minis.

Computer Control Company, USA

Master Control Program. Was the control program for Fujitsu's medium general-purpose computers FACOM 230-20 and FACOM 230-30.

Fujitsu, Japan

Multi-Programming Variable Tasks. Had up to 15 application regions defined dynamically, plus additional regions for system tasks

IBM, USA

Tape and Disk Operating System.

Basic Operating System. Early interim version of DOS/360, briefly available at a few Alpha & Beta System/360 sites

IBM, USA

Monitor System for the PDP-6.

USA

Operating system for IBM Mainframes.

IBM, USA

Operating system for the MELCOM 3100 series of computers. This operating system used magnetic tapes as external storage and were developed by systematically organizing and enhancing the system programs built up with MELCOM-1530.

Mitsubishi, Japan

Operating system for the MELCOM 3100 series of computers. This operating system used magnetic tapes as external storage and were developed by systematically organizing and enhancing the system programs built up with MELCOM-1530.

Mitsubishi, Japan

Operating system for the MELCOM 3100 series of computers. This operating system used magnetic tapes as external storage and were developed by systematically organizing and enhancing the system programs built up with MELCOM-1530.

Mitsubishi, Japan

Disk operating systems for 2314 Disk Access Strorage.

IBM, USA

First control program for FACOM 230-50, developed through improving FONTAC MONITOR. for batch processing based on a magnetic tape.

Fujitsu, Japan

GEneral ORGanisational Environment. Used by ICL 1900 series mainframes.

ICL, UK

Real-time computer system first produced by Hewlett Packard in 1966 and discontinued in 2000.

Hewlett-Packard, USA

Or The RL Monitor System. Discontinued operating system developed for the PDP-8. It was submitted to DECUS in 1970.

Richard F. Lary, USA

Serial batch and multiprogramming OS for the English Electric KDF9, designed to support program development.

English Electric, UK

First official OS targeted for the System/360 architecture.

IBM, USA

Disk operating system developed for models 20 and 40 of Mitsubishi Electric's MELCOM-3100.

Mitsubishi, Japan

Primary Control Program. Early batch-serial version of IBM OS/360.

IBM, USA

Original Multi-programming with a Fixed number of Tasks, replaced by MFT II. See OS/MFT.

IBM, USA

Discontinued operating system released by DEC for their PDP-8 line of mini-computers.

DEC, USA

IBM's Time-sharing System for the S/360-67. Never officially released, canceled in 1969 and again in 1971.

IBM, USA

Time Sharing eXecutive.

IBM, USA

Minimum Operating System. Card-based batch monitor for Univac 9200, 9300.

USA

Cambridge Monitor System or Conversational Monitor System. Single User Interactive OS developed in conjunction with the Virtual Machine Control Program CP-40 at IBM Cambridge Laboratories. Later adapted for CP-67 and VM/370.

IBM, USA

Multi Programming eXecutive. First IBM system to provide multiple fixed partitions into which programs could be scheduled on the basis of external events, time-of-day clock, time interval, operator command and the batch job control language.

IBM, USA

Operating system for TOSBAC-5100/20. Was capable of continuously executing batch jobs using a magnetic tape.

Toshiba, Japan

Operating system for the Unisys ClearPath Dorado family of mainframe systems.

Unisys, USA

Timesharing monitor.

Stanford University, USA

Operating system for the IBM System/360.

Stanford University, USA

Michigan Terminal System, developed by a group of universities in the US, Canada, and the UK for the IBM System/360 Model 67, System/370 series, and compatible mainframes.

IBM, USA

Predecessor to CP-67 on modified IBM System/360 Model 40.

IBM, USA

Also known as CP/CMS. Virtual machine control program for the IBM 360/67. Successor to CP-40. See also CMS.

IBM, USA

Multiprogramming with a Variable number of Tasks. Level of OS/360.

IBM, USA

Disk operating system developed for model 40 of Mitsubishi Electric's MELCOM-3100.

Mitsubishi, Japan

Operating system based on the concurrently developed implemenation of POP-2; Multipop employed no conventional hardware protection mechanisms: its security was guaranteed by accessing system resources via closures of device access functions, and on built in restrictions on code generation embodied in the compiler (an ancient example of a no-kernel system).

Robin Popplestone, USA

Multiprogramming with a Fixed number of Tasks. Simple version of OS/MVT suitable for processors with limited memory.

IBM, USA

Multiprogramming with a Variable Number of Tasks. Popular OS for IBM 360/370.

IBM, USA

Time-sharing system for the IBM S/360-67 and successors.

University of Michigan, USA

Incompatible Timesharing System. Famous OS developed by hackers at MIT's AI lab from 1967 to the early 1980's for the DEC PDP-6 and PDP-10 family.

MIT, USA

Timesharing operating system for the Titan.

Cambridge University, UK

SAIL, Stanford Artificial Intelligence Laboratory. Time-sharing system for DEC PDP-6 and PDP-10, later TOPS-10.

DEC, USA

Operating system for the RC-4000 Computer.

Regnecentralen, Denmark

First-Generation Operating Systems for the TOSBAC-1100E office computer.

Toshiba, Japan

Multi-Job Control System. Enabled the user to perform real-time inquiry operations from up to 16 terminals (electric typewriters) directly connected to the main unit.

Toshiba, Japan

An early Timesharing system developed for the IBM S/360.

University of Pittsburgh, USA

Operating system for the Honeywell Series 200.

USA

Control program for batch processing based on a magnetic drum unit. Job stacking function was added to achieve increased batch processing efficiency.

Fujitsu, Japan

Oerating system for Fujitsu’s large general-purpose computer FACOM 230-60.

Fujitsu, Japan

Primary OS for RCA Spectra 70 And Hitachi HITAC computers.

RCA, USA

Discontinued time-sharing operating system. DEC also referred to it as Timeshared-8 and EduSystem 50.

DEC, USA

Batch Serial Operating System for the SEL 810A/810B minicomputer.

USA

Airline Control Program. In contrast to previous airline transaction processing systems, the most notable aspect of ACP is that it was designed to run on most models of the IBM System/360 mainframe computer family.

IBM, USA

Range of operating systems for Norsk Data's line of minicomputers.

Norwegian Institute of Technology, Norsk Data, Norway

Cambridge Multiple Access System.

University of Cambridge, UK

Multiprogramming OS for NCR Century 300 computer.

USA

Customer-Oriented Optimum Language. Decimal machine language and operating system for the Melcom 81 computers.

Mitsubishi, Japan

Virtual machine for the IBM 360/30.

USA

Operating system for TOSBAC-5100/30.

Toshiba, Japan

Control Program/Cambridge Monitor System.

IBM, USA

Experimental OS for the IBM S/360.

USA

Operating system prototype.

IRIA, France

Operating system for Honeywell Series 200 family.

USA

Operating Systems for UNIVAC 9700.

USA

Disk operating system developed for models 20 and 40 of Mitsubishi Electric's MELCOM-3100.

Mitsubishi, Japan

Operating Systems for UNIVAC 9700.

USA

Dispatcher-68. First operating system for the BESM-6 computer.

ITMiVT RAS, Russia

Operating system for the CDC 6600 based on the concept of a supervisory computer.

Institute for Defense Analyses, USA

Operatingsystem for Control Data 3300/3500.

USA

IBM, USA

Oregon State Open Shop OS. A timesharing system for the CDC 3300.

USA

Research OS developed by Edsgar Dijkstra. Named for the Technische Hoogeschool at Eindhoven, where it was developed. Early exploration of program verification techniques. Early layered system design. First implementation of semaphores.

Technische Hoogeschoo, Netherlands

Virtual Memory Operating System. Timesharing OS for the RCA Spectra 70.

RCA, USA

Multiprogramming system by Dijkstra. Introduced the first form of software-based memory segmentation, freeing programmers from being forced to use actual physical locations.

Eindhoven University of Technology, Netherlands

Experimental Foreground/Background OS for the PDP-8.

USA

Multi-Access OS.

USA

Successor to RCA TSOS. Discontinued computer operating system available for the UNIVAC Series 90 mainframes during the late 1960s through 1980s.

Sperry UNIVAC, USA

An early OS for the PDP-10.

USA

Real-Time Batch Monitor. Capable of simultaneously performing multiple real-time processing tasks.

Xerox, Mitsubishi, Japan

Discontinued operating system developed for the RC 4000 minicomputer .

Regnecentralen, Denmark

Operating system for HITAC 8000 computers. Enhanced functionality based on DOS.

Hitachi, Japan

Uniplexed Information and Computing Service. Later Unix. AT&T, initially on DEC computers.

AT&T, USA

Operating System for the British KDF9.

Leeds University, USA

IBM midrange computer OS.

IBM, USA

Operating system for small-to-medium scale real-time processing.

Fujitsu, Japan

Basic Control Monitor for Xerox/SDS computers.

Scientific Data Systems, USA

Was the first prototype system of the DIPS series.

NTT, Japan

Ancestor of TOPS-20 from BBN, for the PDP-10.

DEC, USA

IBM's Real Time Operating System, ran on 5 NASA custom System/360-75s.

IBM, USA

For medium-scale batch processing. Capable of simultaneously executing one batch process and up to two sub processes.

Fujitsu, Japan

Kent On-Line System.

Kent University, UK

Family of disk operating systems.

Multitasking Real-time OS for 68000 series.

USA

Perpetual Processing OS for Computer Consoles Power 55/5. 68000-based multiple CPUs. UNIX-based system featuring high reliability.

USA

Monitor and Operating system for the PDP-8/S computer system.

United States Naval Postgraduate School, USA

Batch Processing Monitor. Capable of simultaneously performing remote batch processing submitted from a remote location and multiple real-time processing tasks.

Mitsubishi, Japan

Operating system and applications library designed for the PDP-11 family of computers. It was intended as a development platform and research pipewrench for the DARPA/NSF Internet.

David Mills, USA

Distributed real-time OS for laboratory control.

USA

DOS Intel 808x/80x86-based, Disk Operating Systems for desktop systems. Capable of up to 32 users per node. Supported a sophisticated network of nodes that were often purpose-built. The name DOS was used in these products login screens before it was popularized by IBM, Microsoft and others.

DataPoint, USA

Disk Operating System. For real-time systems, providing a filesystem and swapping facilities.

GEC Computers, UK

Operating system for three users, written in Concurrent Pascal, based on SOLO.

Per Brinch Hansen, USA

Operating system for RIAD ES computers.

Russia

See DEC BATCH-11/DOS-11.

IBM, USA

Single User operating system for the GRI-99 Minicomputer.

GRI, USA

Secure Operating System (DOD A1/B3) Multilevel security.

DEC, USA

Adaptation of UNIX, Version 7.

Onyx, USA

ROM-Based Real-time executive.

Destek Group, USA

Paper Tape OS for the Cincinnati Milacron CIP/2200.

USA

Operaing system for the UNIVAC 1108 in a service bureau environment.

Case Western Reserve, USA

Batch oriented disk operating system for the Cincinnati Milacron CIP/2200.

USA

Operating system for CII 1070 and IRIS computers.

Compagnie internationale pour l'informatique, France

Database oriented operating system for MUMPS applications on the PDP-11 and VAX.

DEC, USA

Data Secure Unix. A Security kernel for Unix.

UCLA, USA

System monitor for the BESM computers. Emproved version of D-68. Developped by specialists from the Institute of Atomic Energy. I. V. Kurchatov and the JINR Member States (GDR, Hungary, North Korea).

Ural. Sci. Center (JINR in Dubna), Russia

Parallel OS for the HEP MIMD Computer.

USA

Operating system for a Distributed System developed on the IBM Series/1.

Univeristy of Delaware, USA

First-generation Operating System for the HITAC computers.

Hitachi, Japan

Real time OS for the Modular One.

Chippewa descendent.

Control Data, USA

Operating system for HP 3000.

USA

Interactive Applications System. Operating system for larger PDP-11 systems. Real-time, multiuser, or both.

DEC, USA

Unix-like OS from TSC for DMA-capable, extended addresses, Motorola 6809 based computers; e.g. SWTPC, GIMIX and others.

Technical Systems Consultants (TSC), USA

Version of UNIX for PDP-11.

Uniq Digital Technologies, USA

Wang Word Processing System. Micro-code based system.

Wang Laboratories, USA

Mass storage OS supporting real-time plus batch processing for the CDC System 17.

USA

Control Program. A component of VM/370 for the IBM/370. CP is the kernel which implements the virtual machine.

USA

CP/M like operating system.

Mostek, USA

Small general-purpose computer operating system together with extra functions, such as kana-enabled COBOL, suited for office-computer applications that aimed to be user friendly.

Fujitus, Japan

Modular System Program 7. Real-time OS for the IBM System/7.

USA

Operating system for ES EVM. Comparable to S/360.

Russia

Smoke Signal Broadcasting. A variant of FLEX in most respects.

TSC ?, USA

Operating system for the BESM-6 computer.

IPM, Russia

Modular, core-resident standard operating monitor designes dor use on small or very speclized real-time systems.

Control Data, USA

Batch Processing OS for the Xerox Data Systems SIGMA Computers.

USA

Control Program for Real-Time. Realtime operating system for Xerox 550 and Sigma 9 computer systems.

Xerox, USA

Operating System for UNIVAC 1106 and 1110.

Sperry Univac, USA

Distributed operating system.

University of Wisconsin, USA

Universal Time-sharing Monitor. Operating system for a large-scale system capable of simultaneously performing batch processing, remote batch processing, real-time processing and time-sharing processing.

Mitsubishi, Japan

Operating system for the ARPANET.

Lawrence Roberts, B. Wessler, USA

Commercial single or multiuser OS for small PDP-11 systems.

DEC, USA

Hard Real-Time Operating System for embedded applications that follows the Minimal Real-Time POSIX.13 subset.

University of Cantabria, Spain

Resource System Time Sharing. Multi-user time-sharing operating system, initially developed by Evans Griffiths & Hart of Boston, and acquired by DEC for the PDP-11 series of 16-bit minicomputers.

DEC, USA

Early OSE version for the Zilog Z80 processor.

ENEA, Sweden

Multi-user multiprogramming, database oriented OS for DEC computers.

USA

Multi task operating system for Computer Automation's NAKED computers.

USA

Disk Based Operating System. For General Automation SPC-16 & System 18/30.

General Automation, USA

Real-time OS kernel for a variety of CPUs.

Destek Group, USA

Single Virtual Storage. Refers to Release 1 of Operating System/Virtual Storage 2 (OS/VS2); it is the successor system to the MVT option of Operating System/360.

IBM, USA

Multiple Console Time Sharing System. Developed to support CAD applications at GM.

General Motors, USA

Operating system for Honeywell 200/2000.

USA

Operating system for Cm* Research Multiprocessor.

Carnegie-Mellon University, USA

Message-based OS for the CRAY-1.

Los Alamos, USA

UNIX compatible OS for the PDP-11.

Human Computing Resources, USA

Realtime OS for the Phillips P-855 and P-860.

USA

Also known simply as DOS-11 was the first operating system to run on the Digital PDP-11 minicomputer.

DEC, USA

New Dispatcher. New operating system for the BESM-6 computer. Used in spacecraft flight control centers.

ITMiVT RAS, Russia

Successor to FLEX, which was for Motorola 6800 CPUs.

Technical Systems Consultants (TSC), USA

Small Pascal Operating Environment for the LSI-11.

DEC, USA

Version of UNIX for VAX, developed at the University of California at Berkeley. Late 1970s through early 1990s. Latest version is 4.4.

U.C. Berkeley, USA

Distributed OS for a network of 68000s.

USA

Batch-oriented OS for the CDC 6600.

Lawrence Berkeley Laboratories, USA

Real-Time OS.

General Automation, USA

Operating system written in COBOL.

Data General, USA

Virtual Resource eXecutive. Proprietary operating system on the NCR Criterion series, and later the V-8000 series of mainframe computers manufactured by NCR during the 1970s and 1980s. It replaced the B3 Operating System.

NCR, USA

Realtime executive for General Automation System 18/30.

General Automation, USA

Quadros RTOS proprietary C-based RTOS used in embedded systems.

AT Barrett and Associates, Quadros Systems, USA

Batch operating system for Honeywell System 700.

Honeywell, USA

Operating system for Billings computers.

USA

Kronographic OS. Timesharing OS for CDC 6000 and CYBER computers based on Chippewa. Replaced later by NOS.

Control Data, USA

Free Standing Operating System. Basic memory-resident OS for General Automation SPC-16 mini.

General Automation, USA

Disc operating system for HP-2100.

Hewlett-Packard, USA

Time-sharing operating system with batch and multi-access.

Russia

Time-sharing operating system for airline reservations.

Russia

Operating system for the Tymnet network.

Tymes, USA

Lawrence Timesharing System. Early Timesharing OS.

Lawrence Livermore Labs, USA

Family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix.

Bell Labs, USA

"Ken's new system," for its creator (Ken Thompson), officially Unics and then Unix, the prototypic operating system eated in Bell Labs in 1969 that formed the basis for the Unix family of operating systems.

Bell Labs, USA

Universal Time-Sharing System. Time Sharing Operating System for Xerox SIGMA computers.

Xerox, USA

Primary operating system used on the Digital Equipment Corporation's PDP-8 minicomputer. Ancestor of RT-11.

DEC, USA

Real-time multitasking executive for DEC PDP-15.

DEC, USA

Operating system for Fujitsu’s large-scale general-purpose computers FACOM 230-45S and FACOM 230-55.

Fujitsu, Japan

Dispetcher Paketov. Operating system for the BESM-6 computer. Used in Atomic research.

ITMiVT RAS, Russia

BOS with Multiprocessing of up to 4 jobs.

Fujitsu, Japan

Business oriented operating system for the GRI-99.

USA

Timesharing operating system.

Hewlett-Packard, USA

Disk Operating System.

USA

Timesharing operating system.

Hewlett-Packard, USA

Successor to DOS/360. First DOS offered on System/370 systems, provided virtual storage.

IBM, USA

Sometimes spelled PR1MOS and PR1ME. Written in FORTRAN IV, that didn't have pointers, while later versions, around version 18, written in a version of PL/1, called PL/P.

Prime Computer, USA

Network operating system.

D.J. Farber, K.C. Larson, USA

Real-time Disk Operating System. With variants: RTOS and DOS.

Data General, USA

M. M. Somia, USA

Enhanced version of IBM's DOS/360 (and later DOS/VS and DOS/VSE) operating system for System/360 and System/370 IBM mainframes.

The Computer Software Company (TCSC), USA

Extended version of EDOS.

Hitachi, Japan

Commercial Operating System. Early OS for the PDP.

USA

Simple single-user operating system.

Oxford University, UK

Magnetic Tape OS for Datapoint 1100, 2200, 5500.

Datapoint, USA

Operating system for the MU5 computer.

University of Manchester, UK

Cassette Tape OS for Datapoint 1100, 2200, 5500.

Datapoint, USA

Experimental OS for a modified Interdata minicomputer, based on matching the computer architecture to the operating system.

Barbara Liskov, USA

Realtime multitasking executive for DEC PDP-11. Based on RSX-15.

DEC, USA

McGill University System for Interactive Computing. Operating system developed for the S/370, running normally under VM.

McGill University, USA

Virtual Machine Facility/370. Virtual memory operating system. To assist customers in migration from OS/360 to OS/VS.

IBM, USA

Virtual Machine/Basic Extended Product. Functional ehancement to VM/370.

IBM, USA

Single Virtual Space. Initial release of OS/VS2. Virtual Storage OS for IBM S/370, based closely on OS/MVT.

IBM, USA

Virtual Machine/Extended Product. Functional ehancement to VM/370.

IBM, USA

Port of OS/360 targeted for the System/370 virtual memory architecture, "OS/370" is not correct name for OS/VS1 and OS/VS2, but rather refers to OS/VS2 MVS and MVS/SP Version 1.

IBM, USA

System Executive. A time-sharing monitor for SIGMA/2 and small IBM S/360 computers.

USA

Large-scale software system that supported a virtual space and multiple processors.

Hitachi, Japan

Real-Time Exucutive. Realtime operating system for Hewlett-Packard HP-2000 series.

USA

Time-sharing operating system for the DNEPR-2.

Russia

IBM Virtual Storage OS. See OS/VS1.

IBM, USA

IBM Virtual Storage OS. See OS/VS2.

IBM, USA

First-Generation Operating Systems for the TOSBAC-1350.

Toshiba, Japan

System Control Program. Basic OS for the Burroughs B700 series.

USA

Communications Control Program. Limited OS for the IBM System/3.

IBM, USA

General purpose, multitasking operating system designed to operate with the Texas Instruments 990/10, 990/10A and 990/12 minicomputers using the memory mapping feature.

Texas Instruments, USA

HP Multi-Programming Executive.

Hewlett-Packard, USA

Soviet computer – created using high-level language uЭль-76 (AL-76/ALGOL 68).

Lebedev Institute of Precision Mechanics and Computer Engineering, Russia

Multiprogrammed OS for the PDP-11.

USA

Early version of PICK.

USA

Edinburgh Multi-Access System for ICL 4-75.

University of Edinburgh, UK

Compatible successor to UTS. It supported the same CPUs as UTS plus the Xerox 560.

Xerox, USA

ARGonne Operating System.

Argonne National Laboratory, USA

Used on the 1900 and 290x range of minicomputers. A modified version of Executive was also used as part of GEORGE 3 and 4.

ICL, UK

Experimental, network-wide operating system allowing access to resources distributed on various hosts on the ARPANET based principally on TENEX. The concept have been implemented in the National Software Works (NSW).

R.H. Thomas, USA

Realtime multiprogramming OS for Honeywell System 700.

USA

Virtual Machine Environment. Mainframe operating system. Implementation language S3 (ALGOL 68).

ICL, UK

Operating system for the MERIT network.

Eric Aupperle, USA

Single user OS.

DEC, USA

Business Basic. BASIC language and operating system for Basic Four computers.

MAI Basic Four, USA

Developed for users of small to medium machines with main storage sizes generally ranging between 32 KB and 64 KB.

Hitachi, Japan

Virtual machine OS running on the Michigan Terminal System.

USA

Porgramming language and Operating system for the NEAC System 100 Office computer.

NEC, Japan

Business Executive System for Timesharing. OS for Qantel Minicomputers.

Qantel, USA

Magnetic tape operation system based on 4K disk monitor system (DMS), but reconfigured to improve speed and performance on a magnetic tape.

DEC, USA

Distributed Network Operating System. General purpose, multitasking operating system designed to operate with the Texas Instruments 990/10, 990/10A and 990/12 minicomputers.

Texas Instruments, USA

Basic Operating Software System. Based on UNOS by Charles River Data Systems (CDRS).

MAI Basic Four, USA

Teletype Operating System for the Microdata 1600 & 3200 minicomputers.

USA

Batch OS for the DEC PDP-15.

USA

Real time OS for Mod Comp Computers.

USA

First-Generation Operating Systems for the TOSBAC-1150 office computer.

Toshiba, Japan

Operating System for GEC Computers.

GEC Computers, UK

Operating system adopted for the Unidata series of computers.

Siemens, Germany

Disk OS for DEC PDP-15.

USA

Advanced Comprehensive Operating System-2. Operating system for small computer systems.

NEC, Japan

Portable, modular OS.

University of Warwic, UK

Operating system for Computer Technology minicomputers.

USA

Timesharing OS for the DEC PDP-8.

USA

Monash University Educational Computing System. Was a computer operating system with BASIC, COBOL, FORTRAN, Pascal interpreters, plus machine language facility.

Monash University, Australia

Timesharing OS for General Automation System 18/30.

USA

Experimental local area network architecture.

Cambridge University, UK

Cassette Monitor System for the DEC PDP-11.

DEC, USA

Cassette Monitor system for the DEC PDP-8.

DEC, USA

Large general-purpose operating system that realized multi-dimensional processing.

NEC, Toshiba, Japan

Virtual machine system developed at UCLA for modified PDP-11/45 for data security studies.

UCLA, USA

Cassette OS for Computer Automation Alpha LSI and Naked Mini LSI.

USA

Early (now discontinued) capability-based, object-oriented, microkernel designed to support a wide range of possible operating systems to run on top of it.

Carnegie-Mellon University, USA

Virtual machine system for the IBM 360/67.

USA

Concurrent Operating System. Provided limited multiprogramming for Univac 9200, 9300.

USA

Operating System for GEC Computers.

USA

Standalone OS for Data General Nova & Supernova.

USA

Originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system created for Intel 8080/85-based microcomputers.

Digital Research, USA

Magnetic Tape OS for Computer Automation Alpha LSI & Naked Mini LSI.

Computer Automation, USA

All-round Operating System. The first OS for Office computers.

Mitusbishi, Japan

Magnetic Tape System for HP 2100.

USA

Advanced Operating System for Data General Eclipse and MV series.

Data General, USA

Card/Paper Tape Programming System for the IBM 1130.

IBM, USA

Operating system for Mitsubishi COSMO mainframes.

Mitsubishi, Japan

Discontinued business-oriented mainframe computer real-time operating system. While initially a mini-mainframe, the final high-end systems supported 12 CPUs and over 2000 simultaneous users.

Hewlett-Packard, USA

Multiple Virtual Space. Virtual storage OS for IBM 370, derived from MVT. Originally called VS2, Release 2.

IBM, USA

Real-time monitor for a fixed set of processes linked into a single memory image.

Modular Computer Systems, USA

Operating system for the FACOM V series, developed jointly by Fujitsu, USAC Electronic Industrial and Uchida Yoko.

Fujitsu, Japan

Nonconcurrent OS. Tape or disk based OS for Univac 9200 & 9300.

USA

Tape based OS derived from SCOPE for the CDC System 17.

USA

Omnitasking realtime executive for Varian minicomputers.

USA

Basic Control System for HP-2100.

Hewlett-Packard, USA

Realtime executive for Interdata minicomputers.

USA

Basic Executive & Timekeeper. OS for Varian minicomputers.

USA

Realtime multiprogramming OS for General Automation System 18/30.

USA

Real-Time Disk OS for Interdata Minicomputers.

USA

Real time operating system for Data General Nova.

USA

Virtual Machine system developed on a Burroughs 1700.

USA

Real time multiprogramming OS for Prime 100, 200, 300.

USA

Basic Operating System for the ModComp Computers.

USA

Disk Monitor System for General Automation System 18/30.

USA

Compact real-time operating system designed for the PDP-8 family of processors.

USA

Basic Monitor System.

DEC, USA

Basic OS for Interdata (later Perkin-Elmer) minicomputers.

Interdata, USA

Virtual machine system for the PDP-10.

USA

BOS with Virtual memory control.

Fujitsu, Japan

National Software Works. Descendent of RSEXEC.

Jonathan Postel, USA

Now BS2000/OSD from Fujitsu-Siemens Computers (formerly Siemens Nixdorf Informationssysteme).

Siemens, Germany

Advanced Comprehensive Operating System-4. Small-to-medium machines.

NEC, Japan

Variant of the UNIX operating system used internally at Bell Labs for administrative databases and transaction processing.

Bell Labs, USA

Early disk operating system for the Altair 8800 machine.

MITS, USA

Modular OS for the RCA SUMC Computer (Space Ultrareliable Modular Computer). A realtime OS designed to be modifiable.

S&H Computing, USA

Deep Six Operating System. Was a real-time operating system (sometimes referred to as an operating system kernel) developed by Texas Instruments' Geophysical Services division (GSI).

Texas Instruments, USA

Single-User Research Operating System. Written in Concurrent Pascal, to demonstrate its concurrency mechanism at the California Institute of Technology.

Per Brinch Hansen, USA

Appearing on the ICL 2900 Series and Series 39 mainframes, implemented in S3.

ICL, UK

Real time serial and multitasking operating systems for Interdata (later Perkin-Elmer) 7/16 and 7/32 minicomputers.

USA

Real time serial and multitasking operating systems for Interdata (later Perkin-Elmer) 7/16 and 7/32 minicomputers.

USA

Operating system for a distributed network of PDP-11 virtual machines at the University of Maryland.

David Mills, USA

Hypervisor from Fujitsu (formerly Siemens Nixdorf Informationssysteme) designed specifically for use with the BS2000 operating system. It is an EBCDIC-based operating system.

Siemens, Germany

Intel Systems Implementation Supervisor. Was an environment for development of software within the Intel microprocessor family in the early 1980s on their Intellec Microcomputer Development System and clones.

Intel, USA

One of the operating systems for Fujitsu’s FACOM M series general-purpose computers, and was a super-large general-purpose OS.

Fujitsu, Japan

Was the first OS for the HITAC M series, which was a series of Hitachi's general-purpose computers.

Hitachi, Japan

Virtual Storage Operating System. Operating system for the Cyber 205 pipelined processor.

USA

All operating system procedures written in ALGOL 68C, with some closely associated protected procedures in BCPL.

Cambridge University, UK

Event Driven Executive. computer operating system originally developed by IBM for the control of research laboratory devices and experiments.

IBM, USA

Minicomputer OS.

IBM, USA

Discontinued computer operating system developed by Honeywell. It was a backward-compatible work-alike of the Xerox CP-V fully rewritten for Honeywell Level/66 hardware.

Honeywell, USA

Control Programming Support, subset of RPS.

IBM, USA

New name for UNICOS.

USA

Single-tasking operating system.

Technical Systems Consultants (TSC), USA

Operating system for lower models in Hitachi's HITAC M series of general-purpose computers, was the second OS in the M series following VOS2.

Hitachi, Japan

Message-based operating system designed for fault tolerance.

Tandem, USA

Network Operating System. Operating system with time-sharing capabilities. Based on KRONOS.

Control Data, USA

Business Oriented System. Floppy-disk oriented operating system for OKITAC office computers.

Oki, Japan

Business Oriented System. Hard-disk oriented operating system for OKITAC office computers.

Oki, Japan

Proprietary OS used on some of DEC's 36-bit mainframe computers.

DEC, USA

See Berkeley Software Distribution (BSD).

U.C. Berkeley, USA

Renamed THEO in 1983. The first multi-user operating system for 8-bit microprocessor based computers (Z-80 from Zilog).

Phase One Systems, USA

Wang Office Information System. Successor to the WPS. Combined the WPS and VP/MVP systems.

Wang Laboratories, USA

Multitask version of AOS.

Mitusbishi, Japan

Disk Operating system compatible with CP/M.

Cromemco, USA

Programmer's Workbench (PWB/UNIX). Early, now discontinued, version of the Unix operating system created in the Bell Labs Computer Science Research Group of AT&T.

Bell Labs, USA

Terminal Executive Development System. Proprietary operating systems for TI-990 minicomputers.

Texas Instruments, USA

Operating System for microNOVA-based computers.

Data General, USA

Used for application, job control, system programming, implemented in AL-76.

Lebedev Institute of Precision Mechanics and Computer Engineering, Russia

IBM midrange computer OS.

IBM, USA

System Support Program. operating system for the IBM System/34 and System/36 minicomputers. SSP was a command-based operating system.

IBM, USA

DEC's proprietary operating system originally produced for its VAX minicomputer. Renamed "OpenVMS" around version 5.5.

DEC, USA

Multi-User, Multi-Task Disk System.

muPro Inc., USA

Operating system introduced as the successor to GEC DOS, for its range of GEC 4000 series 16-bit, and later 32-bit, minicomputers.

GEC Computers, UK

Originally by DEC and HP now by VMS Software Inc. for the VAX mini-computer range, Alpha and Intel Itanium i2 and i4; later renamed OpenVMS.

DEC, USA

One of the operating systems for Fujitsu’s FACOM M series general-purpose computers, and was a medium-scale general-purpose OS for medium-scale business operations.

Fujitsu, Japan

One of the operating systems for Fujitsu’s FACOM M series general-purpose computers, and was a large general-purpose OS positioned between super-large general-purpose OS OSIV/F4 and medium general-purpose OS OSIV/F2.

Fujitsu, Japan

Operating system which started out as OASIS, a microcomputer operating system for small computers that use the Z80 processor.

Phase One Systems, USA

Virtual-storage Operating System 3. For its IBM-compatible mainframes, based on IBM's MVS.

Hitachi, Japan

"Cut down" UNIX v6 for the low-end PDP-11/10.

Bell Labs, USA

Virtual Processing System/Virtual Machine. Was an operating system that ran on IBM System/370 – IBM 3090 computers at Boston University in general use from 1977 to around 1990, and in limited use until at least 1993.

IBM, USA

Developed jointly by Fujitsu, USAC Electronic Industrial and Uchida Yoko.

Fujitsu, Japan

Default OS on Commodore computers.

Commodore, USA

Used on the VS line of minicomputer systems.

Wang Laboratories, USA

Operating system for the HITAC L-320, a general-purpose intelligent system with such functions as data entry, billing, and remote job entry.

Hitachi, Japan

See Berkeley Software Distribution.

U.C. Berkeley, USA

TRIvial Portable Operating System.

University of Cambridge, University of Bath, MetaComCo, UK

Network oriented OS.

USA

Floppy-disk-oriented OS supplied by Tandy/Radio Shack for their TRS-80 Z80-based line of personal computers. Eventually renamed as LS-DOS or LDOS.

Randy Cook, Tandy, USA

Distributed Processing Control eXecutive. operating system for the IBM 8100 small computer system. written in the PL/S-like PL/DS language.

IBM, USA

An Experimental Provably Secure Operating System.

USA

Support environment for UCSD Pascal, based on an abstract "p-machine." Now distributed by SofTech Microsystems.

University of California, USA

Heath Disk OS. Originally written for the H-8, it ran without modification on the H-89.

Heathkit, Zenith Data Systems, USA

Version of AOS for the Data General Micro-Nova.

USA

Small, user-friendly OS for the Hewlett-Packard 300.

Hewlett-Packard, USA

Portable complete programming environment/operating system/virtual machine developed by a long running student project at UCSD.

University of California San Diego, USA

Version of PICK.

The Ultimate Corp., USA

Modified version of RT-11.

Heathkit, Zenith Data Systems, USA

Small memory-resident OS for the Motorola 68000.

USA

Also known as LMI. Used an operating system written in MIT's Lisp Machine Lisp.

USA

Cray Operating System. OS for the Cray-1 Pipelined Supercomputer.

USA

Operating system for IBM’s principal distributed processing engine.

IBM, USA

IBM midrange computer OS.

IBM, USA

Proprietary operating system developed for the express purpose of running AT&T's large-scale PBX switching equipment.

Bell Labs, USA

One of two major operating systems developed for the Cm* multiprocessor. Based on concept of task forces.

Carnegie-Mellon University, USA

Interactive Multiprogramming Operating System for the NCR Century 8200 series minicomputers.

NCR, USA

Operating System for small PDP-11's attached to a host computer.

USA

Term used to refer to versions of the Unix operating system developed in the Bell Labs Computing Science Research Center.

Bell Labs, USA

Operating system for 8080 and 8086.

Systems & Software, USA

Rochester Intelligent Gateway. Network OS. Influenced Accent and Mach.

University of Rochester, UK

Control Program Facility.

IBM, USA

Basic Operating System for Apple II Computers. It was superseded by ProDOS in 1983.

Apple, USA

Version of UNIX.

Zilog, USA

Standard operating system for DEC VAX. Based on RSX-11.

USA

Operating System for the Z8000.

Zilog, USA

Distributed OS for multiple identical processors (LSI-11s).

University of Wisconsin, USA

Real-time Programming System. Real-time interactive operating system for the IBM Series/1, based on MSP/7 and MPX/1800.

IBM, USA

MS-DOS compatible system for 68000.

Motorola, USA

Operating system designed to emphasize portability.

USA

MVS supported Enterprise System Architecture, horizontal addressing extensions: data only address spaces called Dataspaces. A Unix environment was available starting with MVS/ESA V4R3.

IBM, USA

Drum memory operating systems for office computers.

NEC, Japan

Floppy disk operating systems for office computers.

NEC, Japan

Disk operating systems for office computers.

NEC, Japan

OS for Randal office LINK computers.

Randal Data Systems, USA

OS for Randal office LINK computers.

Randal Data Systems, USA