| 1 | Windows 7 personal computer operating system by Microsoft that was released in 2009 |
| 2 | Windows Server 2008 version of the Windows Server line of server operating systems, based on Windows Vista and released in 2008 |
| 3 | Windows Server 2003 version of the Windows Server line of server operating systems, based on Windows XP |
| 4 | Windows RT discontinued mobile operating system developed by Microsoft |
| 5 | Windows Mobile discontinued family of mobile operating systems by Microsoft |
| 6 | Windows Home Server variant of Windows Server 2003 for home servers, released on 30 January 2007 |
| 7 | Mythbuntu media center operating system based on Ubuntu. |
| 8 | Ubuntu for Android Ubuntu for Android devices |
| 10 | Windows 1.0 first version of Microsoft Windows desktop operating system by Microsoft released on November 20, 1985 |
| 11 | Slackware Linux distribution |
| 12 | BeOS operating system designed for multimedia, personal desktop use, and multiprocessor computers |
| 13 | OS X Mountain Lion ninth major release of OS X |
| 14 | Windows 95 personal computer operating system by Microsoft |
| 15 | Java Card OpenPlatform operating system |
| 16 | |
| 17 | Apple Pascal Apple II operating system and language interpreter |
| 18 | Windows Preinstallation Environment lightweight version of Microsoft Windows for deployment |
| 19 | |
| 20 | Mac OS X Leopard sixth major release of OS X |
| 21 | Bada mobile operating system |
| 22 | Windows XP Professional x64 Edition an operating system derived from Windows Server 2003 for personal computers with the x64 CPU architecture |
| 23 | |
| 24 | Palm OS mobile operating system |
| 25 | |
| 26 | RMX real-time operating system, originally developed by Intel, for use with 8080 and 8086 systems |
| 27 | leJOS LEGO Mind Storm Java Operating System |
| 28 | VSE IBM mainframe operating system, originally designed for smaller mainframes, successor to DOS/360 |
| 29 | |
| 30 | Amiga Unix operating system |
| 31 | RT-11 single-user real-time operating system for DEC PDP-11 minicomputers |
| 32 | webOS Linux-based mobile operating system |
| 33 | BSD/OS proprietary version of the BSD operating system |
| 34 | |
| 35 | Proxmox Virtual Environment Linux distribution for server virtualization |
| 36 | Apple SOS 8-bit Apple III operating system |
| 37 | Apple GS/OS Apple IIGS operating system |
| 38 | Mastercam CAD/CAM software by CNC Software |
| 39 | Versatile Real-Time Executive real-time operating system |
| 40 | Soft Hard Real-Time Kernel operating system |
| 41 | |
| 42 | AmigaOS operating system of Amiga computers |
| 43 | Mac OS X Snow Leopard seventh major release of OS X |
| 44 | |
| 45 | System 7 Apple Macintosh operating system version series |
| 46 | |
| 47 | |
| 48 | Visi On Visi On was a graphical User Interface for MS-DOS from the software producer Visicorp. |
| 49 | Arthur operating system Early Acorn Computers RISC operating system; later versions known as RISC OS |
| 50 | FreeDOS freely-licensed PC-compatible DOS clone |
| 51 | Mac OS X Lion eighth major release of Mac OS X |
| 52 | Mac OS X 10.1 second major release of OS X |
| 53 | OpenVMS computer operating system |
| 54 | Windows 2.0 16-bit Microsoft Windows GUI-based operating environment |
| 55 | Windows Embedded Compact operating system subfamily by Microsoft |
| 56 | Windows NT 4.0 pre-emptive, graphical operating system by Microsoft |
| 57 | Windows 3.0 third major release of Microsoft Windows |
| 58 | Ultrix DEC operating system |
| 59 | Mac OS X 10.2 thirth major release of OS X |
| 61 | openMosix comouter operating system |
| 62 | Mac OS X Server 1.0 operating system developed by Apple |
| 63 | GEORGE 1960s operating system |
| 64 | |
| 65 | Visopsys 32-bit operating system for PC |
| 66 | disk operating system type of operating system |
| 67 | Singularity operating system |
| 68 | Star Trek project Apple Computer prototype operating system |
| 69 | Windows 9x series of Microsoft Windows computer operating systems |
| 70 | |
| 71 | IBM 7090/94 IBSYS early-to-mid 1960s operating system for the scientific line of IBM mainframes |
| 72 | Apple CP/M operating system |
| 73 | Apple DOS family of disk operating systems |
| 74 | Apple ProDOS operating system on Apple II and III series computers |
| 75 | |
| 76 | UNIX System V most-referenced Unix version and starting point for the first versions of POSIX and the Single UNIX Specification |
| 77 | OpenGEU Linux distribution |
| 78 | Interactive Unix operating system |
| 79 | ChorusOS Microkernel real-time operating system |
| 80 | StartOS Chinese Linux distribution developed by YLMF |
| 81 | QNX Unix-like, real-time, embedded operating system |
| 82 | |
| 83 | NetWare computer network operating system developed by Novell, Inc |
| 84 | Mac OS X Tiger fifth major release of Mac OS X |
| 85 | Windows Fundamentals for Legacy PCs thin client operating system from Microsoft |
| 86 | macOS Server Applications provided for macOS |
| 87 | |
| 88 | Banyan VINES Network operating system (obsoleted) |
| 89 | AskoziaPBX proprietary telephone firmware based on Linux |
| 90 | Kid operating system operating system |
| 91 | Windows 3.x released since 1990, is also known as Windows Version 3 and can refer to either an individual or all of the following versions of Microsoft Windows |
| 92 | Mac OS X Panther fourth major release of macOS |
| 93 | Windows NT 3.1 32-bit cross-platform operating system developed by Microsoft and the first member of the Windows NT family that was released on July 27, 1993 |
| 94 | |
| 95 | Atari DOS disk operating system |
| 96 | |
| 97 | MuLinux Linux distribution |
| 98 | MINIX 3 Unix-like operating system |
| 99 | Windows NT 3.5 32-bit cross-platform operating system developed by Microsoft |
| 100 | MVS Operating system for IBM mainframes |
| 101 | Barrelfish experimental computer operating system |
| 102 | BeIA Embedded operating system |
| 103 | Windows Neptune codename for a version of Microsoft Windows under development in 1999 |
| 104 | NeXTSTEP operating system from NeXT Computer |
| 105 | Miracle Linux Linux distribution |
| 106 | |
| 107 | Cray Operating System operating system |
| 108 | Online OS operating system |
| 109 | |
| 110 | Windows NT 3.51 32-bit cross-platform operating system developed by Microsoft |
| 111 | IBM PC DOS discontinued computer operating system |
| 112 | Poseidon Linux Scientific Linux distribution |
| 113 | Android-x86 Mobile device Linux distribution |
| 114 | BlackBerry 10 discontinued proprietary mobile operating system by BlackBerry |
| 115 | BlackBerry OS operating system |
| 116 | |
| 117 | Cosmoe free and open source operating system attempting to build a hybrid on GNU/Linux foundation and OpenBeOS/Haiku code halted at early development |
| 118 | |
| 119 | Mac OS X 10.0 operating system by Apple |
| 120 | HDOS early microcomputer operating system |
| 121 | PlayStation 3 system software system software for the PlayStation 3 |
| 122 | Conversational Monitor System previously Cambridge Monitor System, an IBM mainframe operating system, also known as VM/CMS and CP/CMS |
| 123 | Windows Essential Business Server 2008 server operating system by Microsoft released in 2008 |
| 124 | |
| 125 | |
| 126 | |
| 127 | Convergent Technologies Operating System operating system |
| 128 | V operating system microkernel operating system |
| 129 | |
| 130 | |
| 131 | DesktopBSD operating system |
| 132 | |
| 133 | Windows Nashville cancelled operating system based on Windows 95 |
| 134 | |
| 135 | Windows Embedded Compact 7 Seventh major release of the Windows Embedded CE operating system |
| 136 | Windows XP Embedded operating system for embedded systems |
| 137 | Xbox 360 system software updatable software and operating system |
| 138 | PlayStation Vita system software system software for the PlayStation Vita and PlayStation TV video game consoles |
| 139 | Commodore BASIC V2 BASIC programming language used in Commodore computer |
| 140 | Compatible Time-Sharing System early and influential timesharing operating system developed at MIT in early 1960s for IBM 7090 mainframe |
| 141 | Control Program Facility operating system of the IBM System/38 minicomputer |
| 142 | |
| 143 | |
| 144 | |
| 145 | Rockbox custom firmware for digital media players |
| 146 | Cairo codename for a Microsoft software project |
| 147 | Windows Embedded CE 6.0 embedded operating system by Microsoft released in 2006 |
| 148 | Zeroshell Linux distribution for servers and embedded systems |
| 149 | BESYS 1950s era IBM mainframe operating system developed by Bell Labs |
| 150 | |
| 151 | Newton OS operating system for apple newton PDA |
| 152 | GhostBSD Unix-like, desktop-oriented operating system |
| 153 | Windows Odyssey Cancelled operating system |
| 154 | Open Enterprise Server computing platform for delivery of shared network services |
| 155 | RISC OS computer operating system |
| 156 | Coyote Linux Operative system |
| 157 | SunOS version of the Unix operating system developed by Sun Microsystems for their workstation and server computer systems |
| 158 | Windows 2.1 16-bit Microsoft Windows GUI-based operating environment |
| 159 | GEOS graphical operating system (16-bit) |
| 160 | |
| 161 | KolibriOS operating system written completely in assembly |
| 162 | Windows IoT embedded operating system by Microsoft |
| 163 | Linux for PlayStation 2 Linux distribution for the PlayStation 2 |
| 164 | Burroughs MCP mainframe operating system |
| 165 | TrueNAS open-source operating system designed for file sharing |
| 166 | |
| 167 | |
| 168 | Embeddable Linux Kernel Subset operating system kernel |
| 169 | |
| 170 | |
| 171 | |
| 172 | Lisa OS operating system by Apple |
| 173 | |
| 174 | KERNAL Commodore operating system |
| 175 | PlayStation Portable system software system software for PlayStation Portable |
| 176 | Single User Control Program CP/M compatible operating system |
| 177 | |
| 178 | Windows Embedded Automotive |
| 179 | z/VM 64-bit hypervisor and virtual machine-based operating system for IBM mainframes |
| 180 | |
| 181 | |
| 182 | PC-MOS/386 operating system |
| 183 | Transaction Processing Facility IBM mainframe operating system used for transaction processing |
| 184 | Kylin Chinese computer operating system |
| 185 | |
| 186 | Windows NT 3.1 Advanced Server |
| 187 | |
| 188 | Windows NT Server 4.0 Enterprise Edition |
| 189 | TOPS-20 operating system by Digital Equipment Corporation |
| 190 | |
| 191 | |
| 192 | General Comprehensive Operating System mainframe operating system originally developed by General Electric in 1962; now owned by Groupe Bull |
| 193 | |
| 194 | |
| 195 | |
| 196 | 86-DOS early version of Seattle Computer Products 86-DOS, which later evolved into MS-DOS |
| 197 | |
| 198 | OS/400 operating system for the IBM AS/400 |
| 199 | Atari TOS operating system of the Atari ST range of computers |
| 200 | ChibiOS/RT operating system |
| 201 | TeleSec Chipcard Operating System smart card operating system |
| 202 | |
| 203 | Goobuntu Ubuntu derivative used internally within Google |
| 204 | Incompatible Timesharing System time-sharing operating system developed by MIT |
| 205 | UNIX System III early commercial version of the Unix operating system by AT&T |
| 206 | Windows Home Server 2011 home server operating system |
| 207 | L4Linux Linux distribution |
| 208 | TOPS-10 operating system for DEC PDP-10 |
| 209 | JavaOS operating system with a Java virtual machine as a fundamental component |
| 210 | OS/360 Operating system for IBM S/360 and later mainframes |
| 211 | KallistiOS unofficial operating system for the Sega Dreamcast |
| 212 | OS/390 31-bit operating system for IBM mainframes |
| 213 | MEDINA universal pre-/postprocessor for finite element analysis |
| 214 | UNICOS Operating system for Cray supercomputers |
| 215 | Minerva reimplementation of Sinclair QDOS |
| 216 | machine code monitor primitive operating system and application software |
| 217 | |
| 218 | |
| 219 | |
| 220 | MiNT alternative operating system kernel for the Atari ST system and its successors |
| 221 | |
| 222 | |
| 223 | IS-DOS disk operating system |
| 224 | |
| 225 | ANDOS Russian operating system |
| 226 | TR-DOS disk operating system for the ZX Spectrum |
| 227 | |
| 228 | MidnightBSD operating system |
| 229 | |
| 230 | Series 40 operating system |
| 231 | Windows for Workgroups 3.11 16-bit operating system produced by Microsoft |
| 232 | |
| 233 | |
| 234 | Webconverger discontinued Linux distribution |
| 235 | OsFree open source OS/2-compatible operating system |
| 236 | |
| 237 | MirOS BSD operating system |
| 238 | Prologue operating system developed in France |
| 239 | PTS-DOS computer operating system for x86 processors |
| 240 | Feather Linux Linux distribution |
| 241 | |
| 242 | |
| 243 | Qt Extended operating system |
| 244 | |
| 245 | |
| 246 | |
| 247 | BlackBerry Tablet OS operating system |
| 248 | |
| 249 | Microsoft Forefront line-of-business security software by Microsoft Corporation |
| 250 | MULTOS multi-application smart card operating system |
| 251 | Cosmos open-source operating system building kit |
| 252 | RSTS/E timesharing operating system for DEC PDP-11 minicomputers |
| 253 | |
| 254 | Time Sharing Operating System mainframe operating system from RCA run their Spectra computers |
| 255 | Windows 95 OSR2 Updated version of Windows 95. |
| 256 | Windows CE 5.0 embedded operating system by Microsoft released in 2004 |
| 257 | |
| 258 | UNIX System Services implementation of UNIX on the z/OS operating system |
| 259 | LANtastic personal computer networking system |
| 260 | |
| 261 | FlexOS discontinued modular real-time multiuser multitasking operating system |
| 262 | Windows Small Business Server 2008 |
| 263 | |
| 264 | |
| 265 | |
| 266 | THE multiprogramming system Operating system |
| 267 | Windows XP Media Center Edition Microsoft Windows operating system released in 2001 |
| 268 | SUPER-UX a supercomputer operating system |
| 269 | CP/M-86 discontinued computer operating system for x86 processors |
| 270 | Sinclair QDOS multitasking operating system |
| 271 | |
| 272 | Version 7 Unix 7th Edition of Research Unix alias UNIX Time-Sharing System |
| 273 | |
| 275 | Android Gingerbread version of the Android operating system |
| 276 | Android Honeycomb version of the Android operating system |
| 277 | Android Ice Cream Sandwich version of the Android operating system |
| 278 | |
| 279 | |
| 280 | |
| 281 | |