List of Operating Systems

Operating systems differ in their use, characteristics and their underlying technology. The very first operating systems were not operating systems at all but rather mechanisms to make the computers work. The first real operating systems were introduced in 1960s by corporations like UNIVAC and Control Data Corporation.

Following is a list of operating systems right from the very early ones to the latest ones used today:

Early Operating Systems

• The Compatible Timeshare System (CTSS)
• Incompatible Timesharing System (ITS)
• THE multiprogramming system
• Multics
• MCP
• The Master Program
• RC 4000 Multiprogramming System
• Apple Dos
• Business Operating System (BOS)

Proprietary Operating Systems

Proprietary operating systems are those operating systems that have proprietary rights over them. It means the developers of these operating systems have exclusive rights, patents, trademarks or copyrights over them.

Operating systems by Acorn

• Arthur
• ARX
• MOS
• RISC OS
• RISC iX

Operating systems by Amiga

• Amiga OS
• Amix (Amiga Unix)

Operating system by Apollo

• AEGIS/Domain/OS

Operating systems by Apple

• Apple II
• Apple DOS
• ProDOS
• GS/OS
• Apple III
• Sophisticated Operating System (SOS)
• Lisa OS
• Macintosh
• Mac OS
• System Software 1
• System Software 2
• System Software 3
• System Software 4
• System Software 5
• System Software 6
• System 7
• Mac OS 8
• Mac OS 9
• Unix-based
• A/UX
• MkLinux
• Mac OS X
• Mac OS X v10.0 (Cheetah)
• Mac OS X v10.1 (Puma)
• Mac OS X v10.2 (Jaguar)
• Mac OS X v10.3 (Panther)
• Mac OS X 10.4 (Tiger)
• Mac OS X v10.5 (Leopard)
• Mac OS X 10.6 (Snow Leopard)
• Mac OS X Server
• Darwin (based on FreeBSD and NextStep)
• iPhone OS
• Apple Newton OS
  

Operating systems by Atari

• Atari DOS
• Atari TOS
• Atari MultiTOS

Operating systems by Be Inc

• BeOS
• BeIA
• ZETA
  

Operating systems by Burroughs/Unisys

• BTOS
• MCP (Burroughs Large Systems)

Operating system by Convergent Technologies

• CTOS

Operating systems by Digital/Tandem Computers/Compaq/Hewlett-Packard

• OS/8
• ITS
• Multi-Programming Executive
• TOPS-10
• WAITS
• TENEX
• TOPS-20
• RSTS/E
• RSX-11
• RT-11
• VMS
• Domain/OS
• RTE HP's Real Time Executive
• TSB HP's Time Share Basic
• Unix-based
• Digital UNIX
• HP-UX
• Ultrix
• Guardian
• OSS
  

Operating system by Fujitsu

• Town OS

Operating systems by Green Hills Software

• INTEGRITY
• INTEGRITY-178B

Operating system by Intel

• iRMX
  

Operating systems by International Business Machines (IBM)

• IBM 7090/94 IBSYS
• SYSTEM 1400/1800 IJMON
• BOS/360
• TOS/360
• DOS/360
• DOS/360/RJE DOS/360
• DOS/VSE
• DOS/VSE/ESA DOS/VSE
• z/VSE
• OS/360
• Primary Control Program (PCP)
  
• Multi-Programming Fixed Tasks (MFT)
• Multi-Programming Variable Tasks (MVT)
• Real Time Operating System (RTOS)
• OS/370
• OS/VS1
• OS/VS2
• Single Virtual Storage (SVS)
• Multiple Virtual Storage (MVS)
• MUSIC/SP
• OS/390
• z/OS z/Architecture
• TPF z/OS
• Control Program/Cambridge Monitor System (CP/CMS)
• Virtual Machine/Conversational Monitor System (VM/CMS)
• Virtual Machine/eXtended Architecture (VM/XA)
• Virtual Machine/Extended System Arcitecture (VM/ESA)
• z/VM
• IBM System/34, 36 System Support Program (SSP)
• OS/400
• i5/OS
• Unix-based
• AIX
• AOS (BSD Unix Version)
• PC-DOS
• OS/2 (with collaboration from Microsoft)
• OS/2 Warp
• eComStation
• IBM 8100 DPCX
• IBM 8100 DPPX
• K42
• Event Driven Executive (EDE/EDX)
• Realtime Programming System (RPS)

Operating systems by International Computers Limited (ICL)

• GEneral ORGanisational Environment (GEORGE)
• VME
  

Operating system by LynuxWorks

• LynxOS

Operating system by Micrium

• MicroC/OS-II

Operating systems by Microsoft

• Xenix
• MSX-DOS
• MS-DOS (with collaboration from IBM)
• Windows CE (Operating System for Handheld devices, Embedded Devices and Realtime Applications)
• Windows CE 3.0
• Windows Mobile
• Windows CE 5.0
• Windows CE 6.0
• Windows 1.0
• Windows 2.0
• Windows 3.0
• Windows 3.1x
• Windows 95
• Windows 98
• Windows Millennium Edition (Windows Me)
• OS/2 (with collaboration from IBM)
• Windows New Technology (NT) Operating Systems
• Windows NT 3.1
• Windows NT 3.5
• Windows NT 3.51
• Windows NT 4.0
• Windows 2000
• Windows XP (XP Home/XP Professional)
  
• Windows Server 2003
• Windows Fundamentals for Legacy PCs
• Windows Vista (Vista Home, Vista Business, Vista Ultimate)
  
• Windows Home Server
• Windows Server 2008
• Windows Vienna (Windows 7)
• Singularity
• Midori
  

Operating systems by Novell

• Novell Netware
• SUSE Linux

Operating system by Quantel

• Business Executive System for Timesharing (BEST)
  

Operating system by RCA

• Timesharing Operating System (TSOS)

Operating systems by The SCO Group

• Xenix
• Xenix 286
• Xenix 386
• SCO Unix
• System V Release 3.2
• SCO Open Desktop
• SCO OpenServer 5
• UnixWare 2.x
• UnixWare 7
• SCO OpenServer 6

Operating systems by Unicoi

• Fusion RTOS (Fusion Realtime Operating System)
• DSPOS

Operating systems by Wind River Systems

• VxWorks

Free Unix Based and Open Source Operating Systems

• Berkeley Software Distribution (BSD)
• FreeBSD
• DesktopBSD
• PC-BSD
• DragonFly
• NetBSD
• OpenBSD
• GNU
• Linux
• OpenDarwin
• OpenSolaris
• SSS-PC
• Syllable
• VSTa
• Ubuntu
  

Other Open Source Non-Unix Based Operating Systems

• FullPliant
• FreeDOS
• FreeVMS
• Haiku
• ReactOS
• osFree

Web operating systems

• DesktopTwo
• G.ho.st
• YouOS
• Browser OS
• eyeOS
• Jooce

Known operating systems with Artificial Intelligence (AI)

• Psyclone (available free for non-commercial purposes)