OSF/1 is a variant of the

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ...

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

developed by the

Open Software Foundation The Open Software Foundation (OSF) was a not-for-profit industry consortium for creating an open standard for an implementation of the operating system Unix. It was formed in 1988 and merged with X/Open in 1996, to become The Open Group. Despite ...

during the late 1980s and early 1990s. OSF/1 is one of the first operating systems to have used the

Mach kernel Mach () is a kernel developed at Carnegie Mellon University by Richard Rashid and Avie Tevanian to support operating system research, primarily distributed and parallel computing. Mach is often considered one of the earliest examples of a microke ...

developed at

Carnegie Mellon University Carnegie Mellon University (CMU) is a private research university in Pittsburgh, Pennsylvania. One of its predecessors was established in 1900 by Andrew Carnegie as the Carnegie Technical Schools; it became the Carnegie Institute of Technology ...

, and is probably best known as the native Unix operating system for

DEC Alpha Alpha (original name Alpha AXP) is a 64-bit reduced instruction set computer (RISC) instruction set architecture (ISA) developed by Digital Equipment Corporation (DEC). Alpha was designed to replace 32-bit VAX complex instruction set computers ...

architecture systems. In 1994, after AT&T had sold

UNIX System V Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, an ...

Novell Novell, Inc. was an American software and services company headquartered in Provo, Utah, that existed from 1980 until 2014. Its most significant product was the multi-platform network operating system known as Novell NetWare. Under the lead ...

and the rival Unix International consortium had disbanded, the Open Software Foundation ceased funding of research and development of OSF/1. The

Tru64 UNIX Tru64 UNIX is a discontinued 64-bit UNIX operating system for the Alpha instruction set architecture (ISA), currently owned by Hewlett-Packard (HP). Previously, Tru64 UNIX was a product of Compaq, and before that, Digital Equipment Corporation ( ...

variant of OSF/1 was supported by HP until 2012.

Background

In 1988, during the so-called "

Unix wars The Unix wars were struggles between vendors to set a standard for the Unix operating system in the late 1980s and early 1990s. Origins Although AT&T Corporation created Unix, by the 1980s, the University of California, Berkeley Computer Syste ...

Digital Equipment Corporation Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president unt ...

(DEC) joined with IBM,

Hewlett-Packard The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company headquartered in Palo Alto, California. HP developed and provided a wide variety of hardware components ...

, and others to form the

(OSF) to develop a version of Unix named OSF/1. The aim was to compete with

System V Release 4 Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, an ...

from

AT&T Corporation AT&T Corporation, originally the American Telephone and Telegraph Company, is the subsidiary of AT&T Inc. that provides voice, video, data, and Internet telecommunications and professional services to businesses, consumers, and government agen ...

and

Sun Microsystems Sun Microsystems, Inc. (Sun for short) was an American technology company that sold computers, computer components, software, and information technology services and created the Java programming language, the Solaris operating system, ZFS, the ...

, and it has been argued that a primary goal was for the operating system to be free of AT&T

intellectual property Intellectual property (IP) is a category of property that includes intangible creations of the human intellect. There are many types of intellectual property, and some countries recognize more than others. The best-known types are patents, cop ...

. The fact that OSF/1 is one of the first operating systems to have used the Mach kernel is cited as support of this assertion. Digital also strongly promoted OSF/1 for

real-time Real-time or real time describes various operations in computing or other processes that must guarantee response times within a specified time (deadline), usually a relatively short time. A real-time process is generally one that happens in defined ...

applications, and with traditional UNIX implementations at the time providing poor real-time support at best, the real-time and multi-threading support can be interpreted as having been heavily dependent on the Mach kernel. It also incorporates a large part of the

BSD The Berkeley Software Distribution or Berkeley Standard Distribution (BSD) is a discontinued operating system based on Research Unix, developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berk ...

kernel (based on the 4.3-Reno release) to implement the UNIX

API An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software Interface (computing), interface, offering a service to other pieces of software. A document or standa ...

. At the time of its introduction, OSF/1 became the third major flavor of UNIX together with

System V Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, an ...

and BSD.

Vendor releases

DEC's first release of OSF/1 (OSF/1 Release 1.0) in January 1992 was for its line of MIPS-based

DECstation The DECstation was a brand of computers used by DEC, and refers to three distinct lines of computer systems—the first released in 1978 as a word processing system, and the latter (more widely known) two both released in 1989. These compri ...

workstations, however this was never a fully supported product. DEC ported OSF/1 to their new

Alpha AXP Alpha (original name Alpha AXP) is a 64-bit reduced instruction set computer (RISC) instruction set architecture (ISA) developed by Digital Equipment Corporation (DEC). Alpha was designed to replace 32-bit VAX complex instruction set computers ( ...

platform as DEC OSF/1 AXP Release 1.2, released in March 1993. OSF/1 AXP is a full

64-bit In computer architecture, 64-bit Integer (computer science), integers, memory addresses, or other Data (computing), data units are those that are 64 bits wide. Also, 64-bit central processing unit, CPUs and arithmetic logic unit, ALUs are those ...

operating system. After OSF/1 AXP V2.0 onwards,

compatibility was also integrated into the system. OSF/1 v2 was also released for DECStation MIPS systems the same year. Subsequent releases are named Digital UNIX, and later,

. HP also released a port of OSF/1 to the early

HP 9000 HP 9000 is a line of workstation and server computer systems produced by the Hewlett-Packard (HP) Company. The native operating system for almost all HP 9000 systems is HP-UX, which is based on UNIX System V. The HP 9000 brand was introduced in ...

/700 workstations based on the

PA-RISC PA-RISC is an instruction set architecture (ISA) developed by Hewlett-Packard. As the name implies, it is a reduced instruction set computer (RISC) architecture, where the PA stands for Precision Architecture. The design is also referred to as ...

1.1 architecture. This was withdrawn soon afterwards due to lack of software and hardware support compared to competing operating systems, specifically

HP-UX HP-UX (from "Hewlett Packard Unix") is Hewlett Packard Enterprise's proprietary implementation of the Unix operating system, based on Unix System V (initially System III) and first released in 1984. Current versions support HPE Integrity Ser ...

. As part of the

AIM alliance The AIM alliance, also known as the PowerPC alliance, was formed on October 2, 1991, between Apple, IBM, and Motorola. Its goal was to create an industry-wide open-standard computing platform based on the POWER instruction set architecture. It ...

and the resulting

PowerOpen The PowerOpen Environment (POE), created in 1991 from the AIM alliance, is an open standard for running a Unix-based operating system on the PowerPC computer architecture. History The AIM alliance was announced on October 2, 1991, yielding th ...

specification,

Apple Computer Apple Inc. is an American multinational technology company headquartered in Cupertino, California, United States. Apple is the largest technology company by revenue (totaling in 2021) and, as of June 2022, is the world's biggest company b ...

intended to base

A/UX A/UX is Apple Computer's Unix-based operating system for Macintosh computers, integrated with System 7's graphical interface and application compatibility. Launched in 1988 and discontinued in 1995 with version 3.1.1, it is Apple's first official ...

4.0 for its

PowerPC PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., App ...

-based

Macintosh The Mac (known as Macintosh until 1999) is a family of personal computers designed and marketed by Apple Inc., Apple Inc. Macs are known for their ease of use and minimalist designs, and are popular among students, creative professionals, and ...

es upon OSF/1, but the project was cancelled and PowerOpen deprecated. IBM used OSF/1 as the basis of the AIX/ESA operating system for

System/370 The IBM System/370 (S/370) is a model range of IBM mainframe computers announced on June 30, 1970, as the successors to the System/360 family. The series mostly maintains backward compatibility with the S/360, allowing an easy migration path f ...

and

System/390 The IBM System/390 is a discontinued mainframe product family implementing the ESA/390, the fifth generation of the System/360 instruction set architecture. The first computers to use the ESA/390 were the Enterprise System/9000 (ES/90 ...

mainframes. OSF/1 was also ported by

Kendall Square Research Kendall Square Research (KSR) was a supercomputer company headquartered originally in Kendall Square in Cambridge, Massachusetts in 1986, near Massachusetts Institute of Technology (MIT). It was co-founded by Steven Frank and Henry Burkhardt I ...

to its proprietary

microarchitecture In computer engineering, microarchitecture, also called computer organization and sometimes abbreviated as µarch or uarch, is the way a given instruction set architecture (ISA) is implemented in a particular processor. A given ISA may be impl ...

used in the KSR1

supercomputer A supercomputer is a computer with a high level of performance as compared to a general-purpose computer. The performance of a supercomputer is commonly measured in floating-point operations per second ( FLOPS) instead of million instructions ...

OSFMK

The Open Software Foundation created OSFMK which is a commercial version of the Mach kernel for use in OSF/1. It contains applicable code from the

University of Utah The University of Utah (U of U, UofU, or simply The U) is a public research university in Salt Lake City, Utah. It is the flagship institution of the Utah System of Higher Education. The university was established in 1850 as the University of De ...

Mach 4 kernel (such as the "Shuttles" modification used to speed up message passing) and applicable code from the many Mach 3.0 variants that sprouted off from the original

Mach 3.0 kernel. It also consists of improvements made by the OSF such as built-in collocation capability, realtime improvements, and rewriting of the IPC RPC component for better performance .

OSF/1 AD

OSF/1 AD (''Advanced Development'') was a

distributed Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations *Probability distribution, the probability of a particular value or value range of a varia ...

version of OSF/1 developed for

massively parallel Massively parallel is the term for using a large number of computer processors (or separate computers) to simultaneously perform a set of coordinated computations in parallel. GPUs are massively parallel architecture with tens of thousands of t ...

supercomputers by

Locus Computing Corporation Locus Computing Corporation was formed in 1982 by Gerald J. Popek, Charles S. Kline and Gregory I. Thiel to commercialize the technologies developed for the LOCUS distributed operating system at UCLA. Locus was notable for commercializing si ...

. Variants of OSF/1 AD are on several such systems, including the

Intel Paragon The Intel Paragon is a discontinued series of massively parallel supercomputers that was produced by Intel in the 1990s. The Paragon XP/S is a productized version of the experimental ''Touchstone Delta'' system that was built at Caltech, launched ...

XP/S and

ASCI Red ASCI Red (also known as ASCI Option Red or TFLOPS) was the first computer built under the Accelerated Strategic Computing Initiative ( ASCI), the supercomputing initiative of the United States government created to help the maintenance of the ...

Convex Convex or convexity may refer to: Science and technology * Convex lens, in optics Mathematics * Convex set, containing the whole line segment that joins points ** Convex polygon, a polygon which encloses a convex set of points ** Convex polytope ...

Exemplar SPP-1200 (as ''SPP-UX'') and the

Hitachi () is a Japanese multinational corporation, multinational Conglomerate (company), conglomerate corporation headquartered in Chiyoda, Tokyo, Japan. It is the parent company of the Hitachi Group (''Hitachi Gurūpu'') and had formed part of the Ni ...

SR2201 (as ''HI-UX MPP'').

References

{{unix-like Discontinued operating systems Mach (kernel) Microkernel-based operating systems Unix variants