Timeline of operating systems

This article presents a timeline of events in the history of computer operating systems from 1951 to the current day. For a narrative explaining the overall developments, see the History of operating systems.

• 1951
  • LEO I 'Lyons Electronic Office' was the commercial development of EDSAC computing platform, supported by British firm J. Lyons and Co.
• 1953
  • DYSEAC - an early machine capable of distributing computing
• 1955
  • General Motors Operating System made for IBM 701
  • MIT's Tape Director operating system made for UNIVAC 1103
• 1956
  • GM-NAA I/O for IBM 704, based on General Motors Operating System
• 1957
  • Atlas Supervisor (Manchester University) (Atlas computer project start)
  • BESYS (Bell Labs), for IBM 704, later IBM 7090 and IBM 7094
• 1958
  • University of Michigan Executive System (UMES), for IBM 704, 709, and 7090
• 1959
  • SHARE Operating System (SOS), based on GM-NAA I/O

• 1960
  • IBSYS (IBM for its 7090 and 7094)
• 1961
  • CTSS demonstration (MIT's Compatible Time-Sharing System for the IBM 7094)
  • MCP (Burroughs Master Control Program) for B5000
• 1962
  • Atlas Supervisor (Manchester University) (Atlas computer commissioned)
  • BBN Time-Sharing System
  • GCOS (GE's General Comprehensive Operating System, originally GECOS, General Electric Comprehensive Operating Supervisor)
• 1963
  • ADMIRAL
  • AN/FSQ-32, another early time-sharing system begun
  • CTSS becomes operational (MIT's Compatible Time-Sharing System for the IBM 7094)
  • JOSS, an interactive time-shared system that did not distinguish between operating system and language
  • Titan Supervisor, early time-sharing system begun
• 1964
  • Berkeley Timesharing System (for Scientific Data Systems' SDS 940)
  • Chippewa Operating System (for CDC 6600 supercomputer)
  • Dartmouth Time-Sharing System (Dartmouth College's DTSS for GE computers)
  • EXEC 8 (UNIVAC)
  • KDF9 Timesharing Director (English Electric) – an early, fully hardware secured, fully pre-emptive process switching, multi-programming operating system for KDF9 (originally announced in 1960)
  • OS/360 (IBM's primary OS for its S/360 series) (announced)
  • PDP-6 Monitor (DEC) descendant renamed TOPS-10 in 1970
  • SCOPE (CDC 3000 series)
• 1965
  • BOS/360 (IBM's Basic Operating System)
  • DECsys
  • TOS/360 (IBM's Tape Operating System)
  • Livermore Time Sharing System (LTSS)
  • Multics (MIT, GE, Bell Labs for the GE-645) (announced)
  • Pick operating system
  • SIPROS 66 (Simultaneous Processing Operating System)
  • THE multiprogramming system (Technische Hogeschool Eindhoven) development
  • TSOS (later VMOS) (RCA)
• 1966
  • DOS/360 (IBM's Disk Operating System)
  • GEORGE 1 & 2 for ICT 1900 series
  • Mod 1
  • Mod 2
  • Mod 8
  • MS/8 (Richard F. Lary's DEC PDP-8 system)
  • MSOS (Mass Storage Operating System)
  • OS/360 (IBM's primary OS for its S/360 series) PCP and MFT (shipped)
  • RAX
  • Remote Users of Shared Hardware (RUSH), a time-sharing system developed by Allen-Babcock for the IBM 360/50
  • SODA for Elwro's Odra 1204
  • Universal Time-Sharing System (XDS Sigma series)
• 1967
  • CP-40, predecessor to CP-67 on modified IBM System/360 Model 40
  • CP-67 (IBM, also known as CP/CMS)
  • Conversational Programming System (CPS), an IBM time-sharing system under OS/360
  • Michigan Terminal System (MTS) (time-sharing system for the IBM S/360-67 and successors)
  • ITS (MIT's Incompatible Timesharing System for the DEC PDP-6 and PDP-10)
  • OS/360 MVT
  • ORVYL (Stanford University's time-sharing system for the IBM S/360-67)
  • TSS/360 (IBM's Time-sharing System for the S/360-67, never officially released, canceled in 1969 and again in 1971)
  • WAITS (SAIL, Stanford Artificial Intelligence Laboratory, time-sharing system for DEC PDP-6 and PDP-10, later TOPS-10)
• 1968
  • Airline Control Program (ACP) (IBM)
  • B1 (NCR Century series)
  • CALL/360, an IBM time-sharing system for System/360
  • Real-Time Executive (RTE) – Hewlett-Packard
  • THE multiprogramming system (Eindhoven University of Technology) publication
  • TSS/8 (DEC for the PDP-8)
  • VP/CSS
• 1969
  • B2 (NCR Century series)
  • B3 (NCR Century series)
  • GEORGE 3 For ICL 1900 series
  • Multics (MIT, GE, Bell Labs for the GE-645 and later the Honeywell 6180) (opened for paying customers in October)
  • RC 4000 Multiprogramming System (RC)
  • TENEX (Bolt, Beranek and Newman for DEC systems, later TOPS-20)
  • Unics (later Unix) (AT&T, initially on DEC computers)
  • Xerox Operating System

• 1970
  • DOS-11 (PDP-11)
• 1971
  • EMAS
  • Kronos
  • RSTS-11 2A-19 (First released version; PDP-11)
  • RSX-15
  • OS/8
• 1972
  • B4 (NCR Century series)
  • COS-300
  • Data General RDOS
  • Edos
  • MUSIC/SP
  • OS/4
  • OS 1100
  • Operating System/Virtual Storage 1 (OS/VS1)
  • Operating System/Virtual Storage 2 R1 (OS/VS2 SVS)
  • PRIMOS (written in FORTRAN IV, that didn't have pointers, while later versions, around version 18, written in a version of PL/I, called PL/P)
  • Virtual Machine/Basic System Extensions Program Product (BSEPP or VM/SE)
  • Virtual Machine/System Extensions Program Product (SEPP or VM/BSE)
  • Virtual Machine Facility/370 (VM/370), sometimes known as VM/CMS
• 1973
  • Эльбрус-1 (Elbrus-1) – Soviet computer – created using high-level language uЭль-76 (AL-76/ALGOL 68)
  • Alto OS
  • CP-V (Control Program V)
  • RSX-11D
  • RT-11
  • VME – implementation language S3 (ALGOL 68)
• 1974
  • ACOS-2 (NEC)
  • ACOS-4
  • ACOS-6
  • CP/M
  • DOS-11 V09-20C (Last stable release, June 1974)
  • Hydra – capability-based, multiprocessing OS kernel
  • MONECS
  • Multi-Programming Executive (MPE) – Hewlett-Packard
  • Operating System/Virtual Storage 2 R2 (MVS)
  • OS/7
  • OS/16
  • OS/32
  • Sintran III
• 1975
  • BS2000 V2.0 (First released version)
  • COS-350
  • ISIS
  • NOS (Control Data Corporation)
  • OS/3 (Univac)
  • VS/9 (formerly RCA's TSOS, later named VMOS)
  • Version 6 Unix
  • XVM/DOS
  • XVM/RSX
• 1976
  • Cambridge CAP computer – all operating system procedures written in ALGOL 68C, with some closely associated protected procedures in BCPL
  • Cray Operating System
  • DX10
  • FLEX
  • TOPS-20
  • TX990/TXDS
  • Tandem Nonstop OS v1
  • Thoth
• 1977
  • 1BSD
  • AMOS
  • KERNAL
  • OASIS operating system
  • OS68
  • OS4000
  • RMX-80
  • System 88 (Exec)
  • System Support Program (IBM System/34 and System/36)
  • TRSDOS
  • Virtual Memory System (VMS) V1.0 (Initial commercial release, October 25)
  • VRX (Virtual Resource eXecutive)
  • VS Virtual Memory Operating System
• 1978
  • 2BSD
  • Apple DOS
  • Control Program Facility (IBM System/38)
  • Cray Time Sharing System (CTSS)
  • DPCX (IBM)
  • DPPX (IBM)
  • HDOS
  • KSOS – secure OS design from Ford Aerospace
  • KVM/370 – security retro-fit of IBM VM/370
  • Lisp machine (CADR)
  • MVS/System Extensions (MVS/SE)
  • OS4 (Naked Mini 4)
  • PTDOS
  • TRIPOS
  • UCSD p-System (First released version)
• 1979
  • Atari DOS
  • 3BSD
  • CP-6
  • Idris
  • MP/M
  • MVS/System Extensions R2 (MVS/SE2)
  • NLTSS
  • POS
  • Sinclair BASIC
  • Transaction Processing Facility (TPF) (IBM)
  • UCLA Secure UNIX – an early secure UNIX OS based on security kernel
  • UNIX/32V
  • DOS/VSE
  • Version 7 Unix

• 1980
  • 86-DOS
  • AOS/VS (Data General)
  • Business Operating System
  • CTOS
  • MVS/System Product (MVS/SP) V1
  • NewDos/80
  • OS-9
  • RMX-86
  • RS-DOS
  • SOS
  • Virtual Machine/System Product (VM/SP)
  • Xenix
• 1981
  • Acorn MOS
  • Aegis SR1 (First Apollo/DOMAIN systems shipped on March 27)
  • CP/M-86
  • iMAX – OS for Intel's iAPX 432 capability machine
  • MCS (Multi-user Control System)
  • MS-DOS
  • PC DOS
  • Pilot (Xerox Star operating system)
  • UNOS
  • UTS
  • V
  • VERSAdos
  • VRTX
  • VSOS (Virtual Storage Operating System)
  • Xinu first release
• 1982
  • Commodore DOS
  • LDOS (By Logical Systems, Inc. – for the Radio Shack TRS-80 Models I, II & III)
  • PCOS (Olivetti M20)
  • pSOS
  • QNX
  • Stratus VOS
  • Sun UNIX (later SunOS) 0.7
  • Ultrix
  • Unix System III
  • VAXELN
• 1983
  • Coherent
  • DNIX
  • EOS
  • GNU (project start)
  • Lisa Office System 7/7
  • LOCUS – UNIX compatible, high reliability, distributed OS
  • MVS/System Product V2 (MVS/Extended Architecture, MVS/XA)
  • Novell NetWare (S-Net)
  • PERPOS
  • ProDOS
  • RTU (Real-Time Unix)
  • STOP – TCSEC A1-class, secure OS for SCOMP hardware
  • SunOS 1.0
  • VSE/System Package (VSE/SP) Version 1
• 1984
  • AMSDOS
  • CTIX (Unix variant)
  • DYNIX
  • Mac OS (System 1.0)
  • MSX-DOS
  • NOS/VE
  • PANOS
  • PC/IX
  • ROS
  • Sinclair QDOS
  • QNX
  • SINIX
  • UNICOS
  • Venix 2.0
  • Virtual Machine/Extended Architecture Migration Assistance (VM/XA MA)
• 1985
  • AmigaOS
  • Atari TOS
  • DG/UX
  • DOS Plus
  • Graphics Environment Manager
  • Harmony
  • MIPS RISC/os
  • Oberon – written in Oberon
  • SunOS 2.0
  • Version 8 Unix
  • Virtual Machine/Extended Architecture System Facility (VM/XA SF)
  • Windows 1.0
  • Windows 1.01
  • Xenix 2.0
• 1986
  • AIX 1.0
  • Cronus distributed OS
  • FlexOS
  • GEMSOS – TCSEC A1-class, secure kernel for BLACKER VPN & GTNP
  • GEOS
  • Genera 7.0
  • HP-UX
  • SunOS 3.0
  • TR-DOS
  • TRIX
  • Version 9 Unix
• 1987
  • Arthur (much improved version came in 1989 under the name RISC OS)
  • BS2000 V9.0
  • IRIX (3.0 is first SGI version)
  • MDOS
  • MINIX 1.0
  • OS/2 (1.0)
  • PC-MOS/386
  • Topaz – semi-distributed OS for DEC Firefly workstation written in Modula-2+ and garbage collected
  • Windows 2.0
• 1988
  • A/UX (Apple Computer)
  • AOS/VS II (Data General)
  • CP/M rebranded as DR-DOS
  • Flex machine – tagged, capability machine with OS and other software written in ALGOL 68RS
  • GS/OS
  • HeliOS 1.0
  • KeyKOS – capability-based microkernel for IBM mainframes with automated persistence of app data
  • LynxOS
  • Mac OS (System 6)
  • MVS/System Product V3 (MVS/Enterprise Systems Architecture, MVS/ESA)
  • OS/2 (1.1)
  • OS/400
  • RISC iX
  • SpartaDOS X
  • SunOS 4.0
  • TOPS-10 7.04 (Last stable release, July 1988)
  • Virtual Machine/Extended Architecture System Product (VM/XA SP)
  • VAX VMM – TCSEC A1-class, VMM for VAX computers (limited use before cancellation)
• 1989
  • Army Secure Operating System (ASOS) – TCSEC A1-class secure, real-time OS for Ada applications
  • EPOC (EPOC16)
  • NeXTSTEP (1.0)
  • OS/2 (1.2)
  • RISC OS (First release was to be called Arthur 2, but was renamed to RISC OS 2, and was first sold as RISC OS 2.00 in April 1989)
  • SCO UNIX (Release 3)
  • TSX-32
  • Version 10 Unix
  • Xenix 2.3.4 (Last stable release)

• 1990
  • AIX 3.0
  • AmigaOS 2.0
  • BeOS (v1)
  • DOS/V
  • Genera 8.0
  • iS-DOS
  • LOCK – TCSEC A1-class secure system with kernel and hardware support for type enforcement
  • MVS/ESA SP Version 4
  • Novell NetWare 3
  • OS/2 1.3
  • OSF/1
  • RTEMS
  • PC/GEOS
  • Windows 3.0
  • Virtual Machine/Enterprise Systems Architecture (VM/XA ESA)
  • VSE/Enterprise Systems Architecture (VSE/ESA) Version 1
• 1991
  • Amoeba – microkernel-based, POSIX-compliant, distributed OS
  • GNO/ME
  • Linux 0.01-0.1
  • Mac OS (System 7)
  • MINIX 1.5
  • PenPoint OS
  • RISC OS 3
  • SUNMOS
  • Trusted Xenix – rewritten & security enhanced Xenix evaluated at TCSEC B2-class
• 1992
  • 386BSD 0.1
  • Amiga Unix 2.01 (Latest stable release)
  • AmigaOS 3.0
  • BSD/386, by BSDi and later known as BSD/OS.
  • LGX
  • OpenVMS V1.0 (First OpenVMS AXP (Alpha) specific version, November 1992)
  • OS/2 2.0 (First i386 32-bit based version)
  • Plan 9 First Edition (First public release was made available to universities)
  • RSTS/E 10.1 (Last stable release, September 1992)
  • SLS
  • Solaris 2.0 (Successor to SunOS 4.x; based on SVR4 instead of BSD)
  • Windows 3.1
• 1993
  • IBM 4690 Operating System
  • FreeBSD
  • NetBSD
  • Novell NetWare 4
  • Newton OS
  • Nucleus RTOS
  • Open Genera 1.0
  • OS 2200 (Unisys)
  • OS/2 2.1
  • PTS-DOS
  • Slackware 1.0
  • Spring
  • Windows NT 3.1 (First Windows NT kernel public release)
• 1994
  • AIX 4.0, 4.1
  • IBM MVS/ESA SP Version 5
  • NetBSD 1.0 (First multi-platform release, October 1994)
  • OS/2 Warp 3.0
  • Red Hat
  • RISC OS 3.5
  • SPIN – extensible OS written in Modula-3
• 1995
  • Digital UNIX (aka Tru64 UNIX)
  • OpenBSD
  • OS/390
  • Plan 9 Second Edition (Commercial second release version was made available to the general public.)
  • SMSQ/E
  • Ultrix 4.5 (Last major release)
  • Windows 95
• 1996
  • AIX 4.2
  • Debian 1.1
  • JN – microkernel OS for embedded, Java apps
  • Mac OS 7.6 (First officially-named Mac OS)
  • OS/2 Warp 4.0
  • Palm OS
  • RISC OS 3.6
  • Windows NT 4.0
  • Windows CE 1.0
• 1997
  • AIX 4.3
  • DR-WebSpyder 1.0
  • EPOC (EPOC32)
  • Inferno
  • Mac OS 8
  • MINIX 2.0
  • Nemesis
  • RISC OS 3.7
  • SkyOS
  • Windows CE 2.0
• 1998
  • DR-WebSpyder 2.0
  • Junos
  • Novell NetWare 5
  • RT-11 5.7 (Last stable release, October 1998)
  • Solaris 7 (first 64-bit Solaris release – names from this point drop "2.", otherwise would've been Solaris 2.7)
  • Windows 98
• 1999
  • Amiga OS 3.5 (unofficial)
  • AROS (Boot for the first time in Stand Alone version)
  • Inferno Second Edition (Last distribution (Release 2.3, c. July 1999) from Lucent's Inferno Business Unit)
  • Mac OS 9
  • OS/2 Warp 4.5
  • RISC OS 4
  • Windows 98 (2nd edition)

• Comparison of operating systems
• List of operating systems
• Comparison of real-time operating systems
• Timeline of DOS operating systems
• Timeline of Linux distributions (Diagram 1992–2010)

• UNIX History – a timeline of UNIX 1969 and its descendants at present
• Concise Microsoft O.S. Timeline – a color-coded concise timeline for various Microsoft operating systems (1981–present)
• Bitsavers – an effort to capture, salvage, and archive historical computer software and manuals from minicomputers and mainframes of the 1950s, 1960s, 1970s, and 1980s
• A brief history of operating systems
• Microsoft operating system time-line