Time-sharing OS for laboratory automation.

USA

Professional Operating System. Standard OS for the PRO-350 and PRO-380. Derived from RSX-11.

DEC, USA

CP/M 2.2 with P2DOS as BDOS replacement.

USA

Discontinued mobile operating system initially developed by Palm for personal digital assistants (PDAs).

Palm, USA

Mobile Operating system based on an Linux core.

Palm, USA

Very resource-light DR DOS 6.0 derivative aimed at the emerging Palmtop/PDA market.

Digital Research, USA

Embedded real time operating system designed to be POSIX compliant.

fentISS, Spain

Operating system for Soviet personal computers BK-0010 and BK-0010-01, intended for programming in the Pascal programming language.

Russia

Embedded operating system.

BSD based OS for Cavium Octeon MIPS architecture processors.

Paxym, USA

IBM's DOS variant, developed jointly with Microsoft.

IBM, Microsoft, USA

Initial release with the first IBM-PC .

Added the DOS Shell, a graphical menu selector, & support for hard disks of >32MB using the format from Compaq DOS 3.31. Also added many bugs and offered less free conventional memory than before. Generally regarded as an unsuccessful release and to be avoided .

Bundles Stacker in place of DriveSpace.

Year 2000-compliant version with minor additional features. Final member of the MS-DOS family .

See GeoWorks.

Berkeley Softworks, USA

Derivated from UNIX System III from AT&T.

IBM, USA

Network OS for MS-DOS or CP/M.

Applied Intelligence, USA

DOS-like, but multiuser/multitasking.

The Software Link, USA

Discontinued NEC port of UNIX System III for their APC III and PC-9801 personal computer. It had extensive graphics capability.

NEC, Japan

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

IBM, USA

Small, inexpensive UNIX lookalike.

Wendin, USA

Small, inexpensive VMS lookalike.

Wendin, USA

Multiuser, multitasking, realtime OS for the 68000, and TI-9900 and 9905.

Eyring Research, USA

Virtual machine system for the PDP-10.

USA

An early OS for the PDP-10.

USA

Monitor System for the PDP-6.

USA

CDC operating system, descendent of Chippewa.

Control Data, USA

Takes the results of the Pegasus project as a starting point on which to build a complete distributed multimedia platform, including toolkits, user interfaces, filing systems and the emulation of familiar software environments.

University of Twente, University of Cambridge, UK

Operating system support for distributed interactive multimedia.

University of Twente, University of Cambridge, UK

Graphical user interface based on PC/GEOS.

Product of GO Corporation and was one of the earliest operating systems written specifically for graphical tablets and personal digital assistants.

GO, USA

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

USA

Written in PERQ Pascal.

PERQ, USA

ROM-based version of CP/M 2.2 for small home computers.

Digital Research, USA

Was only provided for several specific European computers by the manufacturers Siemens PG685 and PC16-20, Apricot PC.

Digital Research, USA

Microsoft Windows clone programmed in a proprietary Object Pascal, by Trumpet Software International (producer of the famous Trumpet Winsock). 32-bit operating system for the PC platform.

Trumpet Software, Tasmania

Open source firewall/router computer software distribution based on FreeBSD.

Rubicon Communications, USA

Based on a concept of persistent virtual memory, and is managed-code oriented. Phantom OS is one of a few OSes that are not based on classical concepts of Unix-like systems.

Digital Zone, Russia

Real-time operating system, used for instance on LabVIEW real-time targets. Now part of IntervalZero.

Pha Lap, USA

Free open-source RTOS for Critical Systems.

CEA, Delphi, Geensys, France

Based on a concept of persistent virtual memory, and is managed-code oriented. Phantom OS is one of a few OSes that are not based on classical concepts of Unix-like systems.

Warsaw University of Technology, Poland

Real-time operating system designed for Internet of Things appliances. Successor to the Phoenix operating system.

Phoenix Systems, USA

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

Prime Computer, Pick Systems, USA

One floppy version of FreeBSD, configured mainly for networking applications. Superseded by NanoBSD.

Michael Bialecki, Poland

Highly configurable and very fast real time operating system. It targets a wide range of architectures, from the small 8 bit processors with very low memory till huge architectures like 32 bit processors with lots of memory.

Real-time operating system for PIC18 microntroller.

Pragmatec, France

Online operating sytem.

Pigeonaut LLC , USA

Certified real time operating system for safety and security critical embedded systems.

SYSGO, Germany

Tiny Linux-like real-time operating system kernel, optimized for ARM Cortex-M series microprocessors. Based on the OSEK/VDX standard.

Full blown 64-bit PicoLisp runs directly on a standard x86-64 PC hardware.

Pilot operating system (used in Xerox Star workstations) was written in the Mesa programming language.

Xerox, USA

Code-name for Taligent OS.

Apple, USA

German Language OS Project.

Dominic Fischer, Switzerland

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

University of Pittsburgh, USA

Distributed OS based on original Unix design principles yet functionally different and going much further.

Bell Labs, USA

Commercial second release version was made available to the general public.

Distributed OS derived from Plan 9 and Off++ microkernel.

Universidad Rev Juan Carlos, Madrid, Spain

Operating system wanted to achieve platform-independence through a low-level VM.

Aka Tropix. Integrated environment (OS/programming language combination) based on Java with a custom native code compiler for x86, an orthogonal persistent Distributed Shared Memory (DSM) for PC clusters, with a consistency model based on restartable transactions coupled with an optimistic synchronization scheme.

Federal University of Rio de Janeiro - UFRJ, Brazil

Partitioned Operating System. Real-time embedded operating system for safety-critical systems (avionics, aerospace). It provides several functionalities and complies with many industrial standards, such as ARINC653 or POSIX. POK was designed to be used in safety-critical systems as well as in public systems.

France

FORTH environment for Z80, 8080, 8086, 6809, 68000, and PDP-11 families.

FORTH, USA

Hobby Unix-like operating system based on ToaruOS.

Real Time Operating System.

Softwave Wireless, France

ROM-Based Real-time executive.

Destek Group, USA

Peter Operating System. OS research project.

Primary OS for RCA Spectra 70 And Hitachi HITAC computers.

RCA, USA

Free and open-source operating system under development primarily for smartphones, based on the Alpine Linux distribution.

Open platform for developing, delivering, and driving real-world, broadband digital and analog video over two-way hybrid fiber coax (HFC) systems.

PowerTV, USA

Open source, royalty-free, real-time operating system for embedded systems. It is designed and implemented for resource-constrained systems that require predictable timing behavior.

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

Version of TSX-PLUS for the PRO-350.

S&H Computer Systems, USA

Name of two similar operating systems for the Apple II series of personal computers. The original ProDOS, renamed ProDOS 8 in version 1.2, is the last official operating system usable by all 8-bit Apple II series computers.

Apple, USA

Stop-gap solution for the 16-bit Apple IIGS that was replaced by GS/OS within two years.

ProDOS renamed ProDOS 8 in version 1.2.

Used to control Soviet Buran space ship.

Russia

Unix clone project for the old 8086 PCs, from former USSR.

Serge Pustovoitoff, Russia

Extremely lightweight stackless threads designed for severely memory constrained systems.

Adam Dunkels, Sweden

An Experimental Provably Secure Operating System.

USA

Portable Software On Silicon. real time operating system (RTOS) and developed/marketed for the first part by Software Components Group (SCG).

Alfred Chao, SCG, ISI, Wind River Systems, USA

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

University of California, USA

Paper Tape OS for the Cincinnati Milacron CIP/2200.

USA

Formally known as PTS-DOS v7.0, which added support for the FAT32 file system.

MS DOS clone.

Phystechsoft, Russia

People's Time Sharing System. A time sharing system for the CDC 6600 based on BKY.

Lawrence Berkeley Laboratories, USA

Operating system at Sandia National Laboratories with a distributed memory architectures.

Sandia National Laboratories, USA

Community project to make Darwin more usable (some people think of it as the informal successor to OpenDarwin.

Proprietary OS for Casio Pocket Viewer.

Casio, Japan

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