Network operating system for the Nexus-series Ethernet switches and MDS-series Fibre Channel storage area network switches made by Cisco Systems.

Cisco, USA

Not Another Completely Heuristic Operating System. Instructional software for teaching undergraduate, and potentially graduate, level operating systems courses.

U.C. Berkeley, USA

Real-time operating system (RTOS) designed to run on micro-controllers for use in sensor networks.

Carnegie-Mellon University, USA

Nanos is a protected mode nanokernel OS for x86 computers. It is written in assembly and assembled with NASM.

Peter Hultqvist, Sweden

Open source operating system for embedded devices that provides the NAS (Network-Attached Storage) server. See XigmaNAS.

Netherlands

NASA OS for CDC computers. Replaced by KRONOS 2.1.

NASA, USA

NASA OS for CDC computers. Replaced by KRONOS 2.1.

NASA, USA

Not Another Scheme OS.

John Kozak, UK

Amstrad CPC native OS.

Amstrad, UK

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

USA

Graphical user interface-based operating system developed for use in Oracle's Network Computers.

Acorn Computers, UK

Soviet MS-DOS 3.0 compatible operating system.

Russia

CP/M-86-like operating system.

Russia

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

ITMiVT RAS, Russia

General purpose Operating System support for multimedia.

University of Cambridge, University of Glasgow, Swedish Institute of Computer Science and Citrix Systems, UK

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

Hitachi, Japan

Soviet RT-11 clone.

Russia

China Standard Software and the National University of Defense Technology strategic partnership to launch a linux version ok Kylin intended for use by government offices, national defense, energy and other sectors of the Chinese economy.

China Standard Software, China

Unix-like OS of the BSD family which focuses on portability and networking and supports tens of platforms.

Open, secure and programable next-generation Network OS.

Pluribus Network, USA

Network operating system providing high-performance network services. Has been superseded by Open Enterprise Server line, which can be based on NetWare or Linux to provide the same set of services.

Novell, USA

Full-featured and robust OS that scales down to meet the constrained resource requirements of realtime embedded systems.

Quantum Software Systems, Canada

Early version of Eden developed for the VAX environment. The name was chosen because it was "far from Eden."

USA

Network OS layer for UNIX systems providing transparent distributed access.

UK

Virtual Machine system developed on a Burroughs 1700.

USA

Third-party OS for Tandy's TRS-80 personal computers.

Apparat, USA

Open source OS with an emphasis on design and portability; it is largely implemented in C/C++, with a small amount of assembly. NewOS kernel is used by Haiku OS.

Travis Geiselbrecht, USA

Discontinued operating system for the Apple Newton PDAs.

Apple, USA

Discontinued computer operating system based on OpenSolaris and Ubuntu that runs on IA-32- and x86-64-based systems. Replaced by Illumian in 2011.

Nexenta Systems, USA

Unix-based OS based on the Mach microkernel.

NeXT, USA

Linux-based real-time OS.

National Instruments, USA

Operating system for the Nixdorf 8890.

USA

Basically a reconstruction of OS-9 for the 6809 Tandy CoCo3, but refined for the Hitachi 6309 compatible CPU.

Bill Nobel, Canada

Network Livermore Timesharing System, also sometimes known as the New Livermore Time Sharing System. Was an operating system that was actively developed at Lawrence Livermore Laboratory.

Lawrence Livermore Labs, USA

Message-based operating system designed for fault tolerance.

Tandem, USA

Disk operating system.

Russia

Simplest operating system for the Soviet personal computers BK-0010.

Russia

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

Control Data, USA

Network Operating System/Batch Environment. Based on SCOPE.

Network Operating System/Virtual Environment.

Preemptive or cooperative scheduling RTOS for microcontrollers.

Jim Tremblay, Canada

CP/M 2.2 with NovaDOS as BDOS replacement.

USA

User interface for NetWare, was a project run by Novell corporation's Advanced Technology Group (ATG).

Novell, USA

Outsourcing project on a technology demo.

Novell, USA

Code name that was given to a secret prototype project, running a port of Mac OS 7 and its applications on Intel-compatible x86 personal computers.

Digital Research, USA

Never released merge of NetWare and UnixWare.

Novell, USA

Single-user, multi-tasking system derived from DR DOS.

Digital Research, USA

Network operating system and the set of network protocols it used to talk to client machines on the network.

Novell, USA

Berkeley Network of Workstations. OS allowing inexpensive workstations to work in cluster, harnessing their resources to match a large computer.

U.C. Berkeley, USA

DOS Like 32BIT "GUI" OS.

LightCone, Japan

Version of MOSIX for National Semiconductor VR32 systems.

USA

National Software Works. Descendent of RSEXEC.

Jonathan Postel, USA

Network Disk Operating System. Working 32-bit, multitasking, OS for x86-based computers, running in protected mode.

NTDIOS, France

Operating System for GEC Computers.

GEC Computers, UK

Real-time operating system (RTOS) supporting 32 and 64 bit embedded platforms. The Nucleus RTOS is designed for real-time embedded systems for use in medical, industrial, consumer, aerospace, and IoT applications.

Mentor Graphics, USA

Real-Time Operating System.

Open source operating system for Ethernut boards.

Ethernut community, Germany

Real-time operating system with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 32-bit microcontroller environments, the primary governing standards in NuttX are POSIX and ANSI standards

Z-System based on CP/M 2.2

Alpha Systems, USA