Free and open-source operating system and Linux distribution based on Debian.

Canonical, Ubuntu community, UK

Canonical agreement with the Ministry of Industry and Information Technology of the People's Republic of China to release an Ubuntu-based Linux OS.

Canonical, UK

Also known as Ubuntu Phone. Mobile version of the Ubuntu operating system that was originally developed by Canonical and is now being developed by the UBports community.

Canonical, UK

Early secure UNIX OS based on security kernel.

UCLA, USA

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

UCLA, USA

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

University of California San Diego, USA

Free operating system built on the FreeDOS kernel with DJGPP.

Micro disk operating system for PC/AT compatibles with legacy floppy drive.

K. Gondow and M. Ohba, Japan

Multi-tasking OS suitable for small embedded µController systems.

Edo Franzi, Switzerland

Version of PICK.

The Ultimate Corp., USA

Originally called Level IV DOS. Operating system for the Tandy TRS-80 Level IV Products.

Vernon Hester, USA

Brand name of Digital Equipment Corporation's (DEC) discontinued native Unix operating systems for the PDP-11, VAX and DECstations.

DEC, USA

Last major release.

Operating system for 8080, 6800, 68000, Z8000 series, and others.

Boston Systems Office, USA

University of Michigan Executive System. Batch operating system.

IBM, USA

MIPS Computers' first operating system, a port of Berkeley's BSD4.3 version of UNIX.

MIPS Computer Systems, USA

Also known as UMIPS/V, UMIPS_V, or UMIPS (System V) was a port of AT&T UNIX System V Release 3.

Virtual machine system for the IBM 360/67.

USA

Network OS for the 8086, 68000, & 16032 families. Multitasking with transparent remote file access, load balancing, and multiple windows. UNIX and PC-DOS compatible.

Lantech Systems, USA

Name of a range of Unix-like operating system variants developed by Cray for its supercomputers. UNICOS is the successor of the Cray Operating System (COS).

Cray, USA

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

AT&T, 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

Discontinued commercial version of the Unix System III and System V operating systems for the 68000.

Unisoft Systems, USA

Version of UNIX for PDP-11.

Uniq Digital Technologies, USA

RTOS 32 Bit Open Standards, Linux Compatible, Ultra Tiny Size, Modularity, POSIX-compliant RTOS that supports a variety of wireless modules and provides a complete set of security protocols.

RoweBots, USA

Pretty standard, kernel based OS.

Michael Gerhards, Germany

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

Unisys, USA

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

Unisys, USA

Version of UNIX for the PDP-11 and VAX.

Human Computing Resources, USA

Server operating system derived from Debian GNU/Linux with an integrated management system for the central and cross-platform administration of servers, services, clients, desktops and users as well as virtualized computers operated in UCS.

Univention, Germany

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

Bell Labs, USA

Early version of the Unix operating system.

Discontinued version of the Unix operating system released by AT&T's Unix Support Group (USG).

The first version of AT&T System V UNIX on the IBM 286 and 386 PCs, ported and sold by Microport.

"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

It is from Version 7 Unix that almost all Unix-based and Unix-like operating systems descend.

Early version of the Unix operating system. 32V was a direct port of the Seventh Edition Unix to the DEC VAX architecture.

Bell Labs, USA

See DMERT.

Bell Labs, USA

Unix operating system. It was originally released by Univel, a jointly owned venture of AT&T's Unix System Laboratories (USL) and Novell.

Univel, Novell, SCO, Caldera Systems, Caldera International, The SCO Group, Xinuos, USA

Based on AT&T System V Release 4.2MP.

UnixWare 2 kernel plus parts of 3.2v5 (UnixWare 2 + OpenServer 5 = UnixWare 7). Referred to by SCO as SVR5.

First, now discontinued, 32-bit Unix-like real-time operating system (RTOS) with real-time extensions.

Charles River Data Systems, USA

Aka Uuu, "operating engine" is "a highly componentized system, where each component can be dynamically loaded, unloaded, replaced at runtime.

Dave Poirier, International

Universal Operating System.

Russia

Operating system for embedded microcontrollers.

Russia

Non-preemptive, multitasking, priority based RTOS.

Real-time development system for 8086, 68000.

United States Software, 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

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

Xerox, USA

Discontinued implementation of the UNIX operating system for IBM mainframe (and compatible) computers.

Amdahl, USA

Operating system for Mitsubishi COSMO mainframes.

Mitsubishi, Japan

Unix-based OS that included both BSD and System V characteristics. It was one of the first Unix based systems to receive NSA's C2 security level certification.

Gould CSD, USA

Family of real-time operating systems.

Green Hills Software, USA

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

Fujitsu, Japan

For small machines.

For medium-sized machines.

For large machines.

For large machines. Upgrade to the UNIOS/F4.