KeyKOS is a persistent

Persistence (computer science)

Persistence in computer science refers to the characteristic of state that outlives the process that created it. Without this capability, state would only exist in RAM, and would be lost when this RAM loses power, such as a computer shutdown....

, pure capability

Capability-based security

Capability-based security is a concept in the design of secure computing systems, one of the existing security models. A capability is a communicable, unforgeable token of authority. It refers to a value that references an object along with an associated set of access rights...

-based operating system

Operating system

An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

 for the IBM

IBM

International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...

 S/370 mainframe

IBM mainframe

IBM mainframes are large computer systems produced by IBM from 1952 to the present. During the 1960s and 1970s, the term mainframe computer was almost synonymous with IBM products due to their marketshare...

 computer

Computer

A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...

s. It allows emulating

Emulator

In computing, an emulator is hardware or software or both that duplicates the functions of a first computer system in a different second computer system, so that the behavior of the second system closely resembles the behavior of the first system...

 the VM

VM (operating system)

VM refers to a family of IBM virtual machine operating systems used on IBM mainframes System/370, System/390, zSeries, System z and compatible systems, including the Hercules emulator for personal computers. The first version, released in 1972, was VM/370, or officially Virtual Machine Facility/370...

, MVS

MVS

Multiple Virtual Storage, more commonly called MVS, was the most commonly used operating system on the System/370 and System/390 IBM mainframe computers...

, and POSIX

POSIX

POSIX , an acronym for "Portable Operating System Interface", is a family of standards specified by the IEEE for maintaining compatibility between operating systems...

 environments. It is a predecessor of the Extremely Reliable Operating System

Extremely Reliable Operating System

EROS is an operating system developed by The EROS Group, LLC., the Johns Hopkins University, and the University of Pennsylvania. Features include automatic data and process persistence, some preliminary real-time support, and capability-based security. EROS is purely a research operating system,...

 (EROS), and its successors, the CapROS

CapROS

CapROS is an open source operating system. It is a pure capability-based system that features automatic persistence of data and processes, even across system reboots. Capability systems naturally support the principle of least authority, which improves security and fault tolerance.CapROS is an...

 and Coyotos

Coyotos

Coyotos is a capability-based security-focused microkernel operating system developed by The EROS Group, LLC. It is a successor to the EROS system that was created at the University of Pennsylvania and Johns Hopkins University.- History :...

 operating systems. KeyKOS is a nanokernel-based operating system.

The development of KeyKOS started under the name GNOSIS

GNOSIS

GNOSIS is a capability-based operating system that was researched during the 1970s in Tymshare, Inc. It was based on the research of Norman Hardy, Dale E. Jordan, Bill Frantz, Charlie Landau, Jay Jonekait, et al. It provided a foundation for the development of future operating systems such as...

 in Tymshare, Inc.

Tymshare

Tymshare, Inc. was headquartered in Cupertino, California from 1964 to 1984.It was a well-known timesharing service and third-party hardware maintenance company throughout its history and competed with companies such as Four Phase, Compuserve, and Digital Equipment Corporation...

 during the 1970s

1970s

File:1970s decade montage.png|From left, clockwise: US President Richard Nixon doing the V for Victory sign after his resignation from office after the Watergate scandal in 1974; Refugees aboard a US naval boat after the Fall of Saigon, leading to the end of the Vietnam War in 1975; The 1973 oil...

 and continued under the name KeyKOS after being bought by Key Logic.

External links

• KeyKOS Home Page
• GNOSIS: A Prototype Operating System for the 1990s, a 1979 paper, Tymshare Inc.
• KeyKOS - A Secure, High-Performance Environment for S/370, a 1988 paper, Key Logic, Inc.