List of the Best Computer Operating System | Top Ten Most Popular OS

Which Operating System is the Best - Vote Now | Top Ten Most Popular OS

If We count the number of Operating System (including particular OS Family), this figure will be more than two thousand. But here we are listing the operating system which is very popular and whose user experience is very positive. We also invite you to share your operating system experience and vote on your favorite OS.

Android is an open source mobile operating system developed by Google, which is based on Linux. There are many features available in this like mobile games, cameras etc. Due to this, Android has become the most used operating system in the present time. Android was developed by Android Inc., a company that was acquired by Google in 2005. The company was later placed by Google in the Open Handset Alliance (OHA). In April 2013, more than 1.5 million Android phones were activated every day. In total, more than 900 million Android devices were activated in May 2013.

Linux is an operating system like Unix. This is the most successful and most popular software of open source software. It is available for general use under the GPL v2 license and part of it is inspired by Unix.

3. Ubuntu

Ubuntu

Ubuntu is a Linux operating system. It first came in October of 2004. It is based on Debian Linux and today there are many other Linux Dictribution based on this such as Linux Mint.

Google Chrome OS is an operating system based on the Linux kernel and uses Google Chrome as the main user interface. As a result, ChromeOS supports Google's web application. It was announced on July 7, 2009, which describes it as an operating system, which stores both users and application data in their cloud server. Chrome OS has a media player and an integrated file manager. It supports the Chrome app, which looks like remote access to the original applications as well as the desktop. Some Android apps are available for operating systems from 2014. Chrome OS Open Source Project is based on Chromium OS, which can be compiled from download source code unlike Chrome OS.

FreeBSD is a free UNIX operating system. The goal of the FreeBSD project is to provide a system that can be used for anything with the least possible restrictions.

6. iOS

iOS

iOS is a mobile operating system of the multinational Apple Inc. Originally developed for the iPhone (iPhone OS), then it has been used on devices such as iPod touch and iPad. It does not allow the installation of iOS on third-party hardware. The control elements consist of sliders, switches and buttons. The response to the user's orders is immediate and provides a fluid interface. The interaction with the operating system includes gestures such as slips, touches, pinches, which have different definitions depending on the context of the interface. Internal accelerometers are used to make some applications respond to shake the device (for example, for the undo command) or rotate it in three dimensions (a common result is to change from landscape to landscape or landscape).

Chromium OS is a Linux distribution unlike Google Chrome OS. The source code is freely available and usable. Chromium OS contains the substring instead of Google Chrome BSD license standing Chromium browser. New Chrome OS version is derived from the current Chromium OS development and are complemented by several commercial programs such as Google Chrome, Adobe Flash, PDF plugin, Netflix and Google Hangouts. Chromium OS was built on the basis of a Linux kernel, in an Ubuntu 10.04 environment, using the official package manager of the Gentoo Linux distribution, Portage.

Fedora is an RPM based Linux distribution. The Fedora project was born from the Warren Togami initiative which needed to create high quality RPM Package Manager packages for Red Hat Linux. On September 25, 2003, the first release of Fedora Core was born, the FC 0.94, also known as Fedora Core 1 test 2 and with the code name Severn. The Fedora project was born from the Warren Togami initiative which needed to create high quality RPM Package Manager packages for Red Hat Linux. Fedora is an RPM based Linux distribution. The goal of the developers of the distribution is to promote Free Software and to design an operating system for as diverse a target group as possible. The development is being organized in the online community of the Fedora project, led by Red Hat. Fedora is the direct successor to Red Hat Linux. The Red Hat company provides jobs to many developers of Fedora, but the company does not provide any business support or services for the distribution.

mac OS formerly known as Mac OS X and after then OS X, this operating system is a series of graphical operating systems developed and marketed by Apple Inc. since 2001. It is the main operating system for Apples Mac computer family. Within the market of desktop, laptop and home computers, and through the use of the web, it is the second most used desktop operating system, after Microsoft Windows.

Red Hat Linux was an operating system based on Linux from the production company Red Hat. Intended for home users, production was stopped in 2004 and stayed release Red Hat Enterprise Linux. Since 2003, Red Hat has shifted its focus to the business market with the Red Hat Enterprise Linux distribution and the non-commercial Fedora Core version. Red Hat Linux 9 the final version, officially arrived at the end of its useful life on April 30, 2004. Although the Fedora Legacy project continued publishing updates, until the project was abandoned at the end of 2006.

11. Haiku

Haiku

Haiku is an open source operating system currently under development that focuses specifically on personal and multimedia computing. Inspired by BeOS (Be Operating System), Haiku aims to become a fast, efficient, easy to use and easy to learn system, without neglecting its power for users of all levels. The project is led by Haiku Inc., a nonprofit organization located in New York. Haiku has its own modular micro nucleus called NewOS, which will be highly optimized for work with audio, video, graphics, and animations in three dimensions inspired by the original BeOS. Its architecture provides advanced core accommodates multiple processors, high performance, bandwidth input/output and a penetrating modular system multi threaded for system re-entrant processes multitasking, graphical flexibility and response Real time, unlike other operating systems Haiku OS is natively graphic, inherited from BeOs, Visual programming by nodes from the outputs of the programs that allow it through a native software called Cortex.

OpenBSD is a Unix like free and open source operating system derived from AT&T UNIX through the Berkeley Software Distribution (BSD) branch, a research Unix derivative developed at the University of California, Berkeley. At the end of 1995, Theo de Raadt branched out from NetBSD. In addition to the operating system as a whole, the project saves a portable version of many subsystems, especially OpenSSH, which is available as a package on other operating systems. This project is known for its developers' insistence on open source code, good documentation, code correctness, and security. This project has a strict policy on licensing, preferring the ISC license and other variations of the simplified BSD license. Many of the security features are optional or not in other system operations. Developers often audit source code for software bugs and security holes. De Raadt coordinated this project from his home in Calgary, Alberta, Canada. The logo and mascot are puffer fish named Puffy.

System 7 is a version of Mac OS, the operating system of Macintosh personal computers introduced on May 13, 1991, and was the main operating system of the Mac until it was replaced by Mac OS 8 in 1997. Features added to System 7 included Cooperative Multitasking, virtual memory, personal file sharing, QuickTime, QuickDraw 3D and an improved graphical interface. Nowadays it is still used by a small number of Macintosh users that use computers based on Motorola 68000 family microprocessors. Note that "System 7" is used as a generic term to refer to all its versions. With the release of version 7.6 in 1997, Apple officially changed the name of the operating system to Mac OS, a name that first appeared in System 7.5.1. System 7 was developed for Motorola 68k processors but was ported to PowerPC, when Apple adopted the use of the new processor.

14. Debian

Debian

SunOS was the version of the operating system derived from UNIX and BSD developed by Sun Microsystems for its workstations and servers until the beginning of the 1990s. This was based on the UNIX BSD with some additions of the System V UNIX in later versions. SunOS is a version of UNIX used in Sun Microsystems workstations which was released in 1982. After releasing SunOS version 4, Sun Microsystems changed the UNIX BSD code they had previously used with the UNIX System V code, after obtaining a license from the UNIX licensee at that time, AT&T. This change made the name change to Solaris version 2, from what SunOS should have been 5. So, indirectly, SunOS was considered as Solaris version 1.x.

16. Mac OS 8

Mac OS 8

Mac OS 8 is an operating system developed and marketed by Apple Computer on 26 of July, 1997. It is the biggest overhaul of Mac OS since the release of System 7.

Ubuntu Privacy Remix (UPR) is a modified live CD based on the Ubuntu Linux distribution. UPR is not intended for permanent installation on the hard disk. UPR developers believe that the threat of theft of sensitive data today is no longer limited to ordinary cyber criminals and their Trojan horses, rootkits and keyloggers. Rather, in many countries of the world, the government is taking measures to spy on and monitor citizens' computers by such means. Ubuntu Privacy Remix is ​​designed as a tool to protect your data against unauthorized access.

18. MenuetOS

MenuetOS

MenuetOS, also known as MeOS, is a free operating system created by Ville Mikael Turjanmaa for PC x86, written entirely in assembly language (FASM) for 32 and 64 bits. It reached version 1.0 on May 15, 2015 for the 64 bit version, considered by its creator as the first official release of the operating system. Its core is real-time, monolithic, with preferred multitasking, which includes video controllers, networks, audio, USB devices, keyboards, TV tuners, webcams and printers, among other types of devices. Its development has focused on the objective of allowing it to develop efficiently, simply and quickly. It has a graphic desktop, games and connectivity, using a TCP/IP stack. Even so, it fits on a flexible disk of 1.44 MB. It also facilitates easy and complete programming in assembly language. This is contrary to the usual view according to which assembly language is only useful in old or embedded systems.

19. JavaOS

JavaOS

JavaOS is an operating system, discontinued since 2006. It was developed by Sun Microsystems and unlike Windows, Mac OS and Unix which are written in the C language, JavaOS is written in Java.

Windows 10 is an operating system for personal computers developed and released by Microsoft as part of the operating system family Windows NT. It was released on July 29, 2015. It is the first version of Windows for which feature updates are constantly being released. Devices in enterprise environments can receive these updates at a slower pace or only receive critical updates, such as security patches, during the ten-year lifetime of extended support. The development of Windows Threshold started shortly after the completion of Windows 8 and simultaneously with the development of Windows 8.1. The update would take a step back from the Windows 8 vision by making the start screen optional. During Build 2014, Microsoft announced some features of "the next iteration of Windows", including the return of the start menu and the ability to run Modern UI apps within the desktop.

Windows NT (Windows New Technology) is a member of Microsoft's operating system, whose first version was published in July 1993. Windows NT Technology is a 32-bit Microsoft operating system designed to work in a large network environment. Windows versions released after 2000 are actually Windows NT but do not officially use this name. Prior to the presence of Windows 95, Microsoft Company conceived and shaped a new line of operating systems oriented for workstation and network servers. In the first instance it was primarily intended for professional use, only with Windows XP is the 'professional' line also intended for home use.

MaRTE OS (Minimal Real-Time Operating System for Embedded Applications) is a real-time operating system that implements the services defined in the POSIX.13 standard. MarteOS is a real-time operating system for embedded applications that follows the minimum real-time POSIX .13. The project is developed by the Computer and Real Time Group at the University of Cantabria, although there are also collaborators in different places. It allows to run embedded applications written in Ada and C. This operating system works either directly on PC or emulator. The development environment is based on the GNU compilers GNAT, GCC and GCJ.

23. Qimo

Qimo

Qimo 4 Kids was a kid-friendly environment, built entirely with free software. Qimo comes pre-installed with educational games for children. The interface has large colorful icons that makes it easy for users to navigate easily. It is designed especially for children of school. It's a pretty simple idea, it's a customized version of Xubuntu, designed to be visually appealing, yet not overwhelming to children. Qimo is based on Xubuntu, maintained by the community derived from the Ubuntu operating system, using the Xfce desktop environment. This helps to provide low hardware requirements, minimum of 256 MB of memory to run from the CD, or 192 MB to install. At least 6 GB of hard disk space is recommended, and a CPU of 400 MHz or higher. Qimo 2.0 was launched in May 2010 and stopped developing in 2012.

Symbian OS is an operating system designed for mobile devices and smartphones, with reference to related libraries, user interfaces, frameworks and common tools that were originally developed by Symbian Limited. It is descended from Psion's EPOC and runs exclusively on ARM processors only. Nokia acquired Symbian Software Limited in 2008 and established a new independent nonprofit organization named Symbian Foundation. Symbian OS and related user interfaces, S60, UIQ and MOAP(S) were donated to the organization by its owners for the purpose of making Symbian platform a royalty free, open source software. This platform was named as the successor to the Symbian OS after the official inauguration of the Symbian Foundation in April 2009. In February 2010, the Symbian platform was officially made available as open source code. It contributed 46.9% on the sale of Symbian-based equipment and smartphones, due to this it became the world's most popular mobile operating system.

25. ReactOS

ReactOS

26. Symobi

Symobi

The basis of Symobi is the message-oriented operating system µnOS, which is on its part based on the real-time microkernel Sphere.

Windows Server 2003 R2 is an improved version of Windows Server 2003 that was released in December 2005, but older users are not free to update to the new version, but require a paid update. However, R2 is currently on the market. In addition to Win2K3 SP1, the content of R2 has another CD, which contains more new features. It is based on NT technology and the version of the NT kernel is 5.2. In general terms, Windows Server 2003 could be considered as a modified Windows XP for business tasks, not with fewer functions, but these are disabled by default to obtain better performance and to center the use of processor in the server characteristics, for example, the graphical interface called Luna in Windows XP is disabled, so only the classic Windows interface is used.

28. NTDIOS

NTDIOS

NTDIOS Networ Disk OS is a working 32-bit, multitasking, OS for x86-based computers, running in protected mode.

29. Zorin OS

Zorin OS

30. USIX

USIX

USIX is a Unix-like operating system created by System Six Inc. and INEUM. USIX, complied with the main international standards and agreements (POSIX 1003.1b-1993, SVID), supported real-time mode, had built-in protection against unauthorized access (security level C2), etc. Binary compatible with SVR4 / 386. After System Six closed, OS development ended.

The Möbius operating system is an open source operating system for the IA-32 platform (Intel i386 and compatible). The authors focused the development on some very important points for a modern operating system. The main objectives of Möbius are: (1). Make it sufficiently extensible to make the development of new device drivers and technologies easier. (2). Keep the kernel as small and modular as possible. (3). Support existing applications whenever possible. (4). Stay easy to use enough to have a Mobius system installed and configured without having to learn anything.

32. COS

COS

Chinese operating system referred to as: COS is a operating system by the Institute of Software, Chinese Academy of Sciences and Shanghai Alliance Tong Network Communications Technology Co., Ltd. This is a  jointly designed and developed operating system, released on January 15, 2014 in Beijing's Diaoyutai State Guesthouse. It claims that the system already has 100,000 applications. It claims that the system already has 100,000 applications. The system uses the Linux kernel to provide a user-level hardware abstraction layer, data layer and media layer, and supports multiple runtime environments. According to reports, the operating system has China's completely independent intellectual property rights, the Chinese Academy of Sciences is intended to break the monopoly of the US series of manufacturers.

Windows 7 is an operating system of the Microsoft Windows family. This computer software is the new operating system released by Microsoft Company on October 23, 2009. Microsoft has made several improvements to make it more user-friendly than its previous operating system 'Vista'. Microsoft says it's the simplest and best operating system in its history. Some features are:- 1. Finding this can be done at a fast pace. 2. Browsing is easier than ever. 3. Better networks - Wi-Fi, mobile broadband corporate VPN etc. can be opened with the help of just one click. 4. Device-friendly - With this help camera, printer etc. can be easily added. 5. Less driver requirement - Most drivers are installed in Windows 7.

34. Windows 98 SE

Windows 98 SE

On June 25, 1998 Microsoft launched Windows 98, which was a better version of Windows 95. It included new hardware drivers and the FAT32 file system that supported partitions larger than the 2GB allowed by Windows 95. This edition is one of the latest for PC-9821. In 1999 Microsoft released Windows 98 second edition, whose most notable feature was the ability to share between several computers an Internet connection through a single telephone line and some improvements to the original Windows 98.

35. Cromix

Cromix

Cromemco released CROMIX, the first Unix-like OS for microcomputers. CROMIX run on Cromemco systems using the Motorola 68000 series of microprocessors.

36. Xenix

Xenix

Xenix is a UNIX descendant operating system that was purchased by Microsoft Corporation from AT&T as a developer of UNIX Version 7 in 1979. This operating system was introduced on August 25, 1980, and became the most popular UNIX operating system of its time.

37. MS-DOS

MS-DOS

MS-DOS (acronym - Microsoft Disk Operating System) was an operating system from Microsoft, now no longer in production. Its dedicated to the personal computer with a microprocessor x86. MS-DOS Marketed from 1982 to 2000, it was the first in a long series of Microsoft operating systems that in the 1980s accounted for over 90% of the global operating system market and, until the advent of Windows 95 in 1995, was the operating system for the most widespread computer in the world. MS-DOS was born in 1980. When tasked with Microsoft to produce an operating system for personal computers range of IBM PC of IBM. At this time, Microsoft bought the rights to QDOS, also known as 86-DOS, of Seattle Computer Products that was developed by Tim Paterson, and began working on the modifications to meet IBM's requirements.

38. Nova

Nova

39. LynxOS

LynxOS

LynxOS is a unixoides real-time operating system of the Californian company Lynx Software Technologies, which primarily on the market of embedded systems is aligned. Although the application areas include predominantly critical applications in military, aerospace, medical, industrial process and control systems as well as telecommunications and consumer electronics.

Windows 8 is an operating system developed by Microsoft for use on computers, laptops and tablets and is the successor to Windows 7. The RTM version was released on August 1, 2012 and the final consumer version has been available since October 26, 2012. TechNet and MSDN users (or another type of account with the option to obtain a license from Windows 8) were able to use the operating system from August 15, 2012. Windows Server 2012 was released at about the same time as Windows 8. Windows 8 was succeeded by Windows 8.1 on October 17, 2013. Windows 8.1 is available for free in the Windows Store for anyone with Windows 8.

41. DSOS

DSOS

DSOS (Deep Six Operating System) was a real-time operating system (sometimes referred to as an operating system kernel) developed by Texas Instruments' Geophysical Services division (GSI) in the mid-1970s.

IDE, ATAPI, soundblaster, FDC, VGA, NE2000, parallel port, serial port, RTC, keyboard, ALI1543 SMB. supported filesystems:- VFAT [FAT32/FAT16/FAT12], NTFS, ext2, CD Filesystem [ISO9660/Rock Ridge Extension/Joliet Extension], HPFS.

brickOS (previously legOS) is an alternative software environment for the Lego Mindstorms Robotic Invention System. The intent is to allow developers to write C and/or C++ code for the RIS platform.

Operating System ISIS (Intel System Implementation Supervisor) was originally developed by Ken Burgett to Intel under the new management Bill Davidow from 1975 for systems Development their Microprocessor (IMDS) processors 8080/8085, and later adapted as ISIS-II for FDD systems.

45. NSK (NonStop Kernel)

NSK (NonStop Kernel)

In 1983, the NonStop TXP CPU was the first reimplementation of the TNS instruction set architecture. It consisted of standard TTL chips and programmable array logic chips, with 4 boards per CPU module. Cache Memory was used for the first time.

μClinux is a Linux distribution with a kernel adapted to microprocessors and microcontrollers without Memory Management Unit.

47. Salgix

Salgix

Salgix is GNU/Linux-based OS developed and maintained by GMSI built with Debian and Ubuntu technology specifically for use on its line of Visual Workstations.

48. Xubuntu

Xubuntu

49. Oracle Linux

Oracle Linux

50. Red Hat Enterprise Linux

Red Hat Enterprise Linux

51. Sabayon

Sabayon

52. Amiga OS

Amiga OS

53. Sinclair

Sinclair

54. VMS

VMS

55. Redox

Redox

56. PowerOS

PowerOS

57. PAKOS

PAKOS

58. ScorchOS

ScorchOS

59. VxWorks

VxWorks

60. PC-MOS/386

PC-MOS/386

61. Chakra

Chakra

62. BlueEyedOS

BlueEyedOS

63. ConvexOS

ConvexOS

64. z/OS

z/OS

65. Lycoris Desktop/LX

Lycoris Desktop/LX

66. OS/2

OS/2

67. AdaOS

AdaOS

68. Linux Lite

Linux Lite

69. Masix

Masix

70. BIG LINUX

BIG LINUX

71. NetMAX DeskTOP

NetMAX DeskTOP

72. FuryBSD

FuryBSD

73. Allegro

Allegro

74. Ultrix

Ultrix

75. Mac OS 9

Mac OS 9

76. Q4OS

Q4OS

77. CentOS

CentOS

78. WinMac

WinMac

79. OS/9

OS/9

80. REXX/OS

REXX/OS

81. Xandros

Xandros

82. FreeDOS

FreeDOS

83. Thix

Thix

84. MOSIX

MOSIX

85. MeeGo

MeeGo

86. Netware

Netware

87. Arch Linux

Arch Linux

88. Firefox OS

Firefox OS

89. BeOS

BeOS

90. Chimera

Chimera

91. Data General

Data General

92. NetBSD

NetBSD

93. UbuntuME

UbuntuME

94. Zebuntu

Zebuntu

95. OppcOS

OppcOS

96. ITS

ITS

97. z-VM

z-VM

98. System 6 (Mac OS)

System 6 (Mac OS)

99. osCAN

osCAN

100. SLAMPP

SLAMPP

101. Spice

Spice

102. DC/OSx

DC/OSx

103. JAMB

JAMB

104. FullPliant

FullPliant

105. Harmony

Harmony

106. OS/2 Warp

OS/2 Warp

107. ThreadX

ThreadX

108. GUIDE

GUIDE

109. KolibriOS

KolibriOS

110. MikeOS

MikeOS

111. TriangleOS

TriangleOS

112. Ufficio Zero

Ufficio Zero

113. Coherent

Coherent

114. ERaMS

ERaMS

115. RTMX

RTMX

116. Zentyal

Zentyal

117. THE

THE

118. PublicOS

PublicOS

119. ProOSEK

ProOSEK

120. Bada

Bada

121. StreamOS

StreamOS

122. PETROS

PETROS

123. Windows Vista

Windows Vista

124. NOS/VE

NOS/VE

125. Raspbian

Raspbian

126. ZotOS

ZotOS

127. SunMOS

SunMOS

128. OS-9

OS-9

129. XtreemOS

XtreemOS

130. Jbed

Jbed

131. L4

L4

132. DesktopBSD

DesktopBSD

133. Fuchsia

Fuchsia

134. RISC OS

RISC OS

135. TinyOS

TinyOS

136. STAR-OS

STAR-OS

137. Urli OS

Urli OS

138. ModulOS

ModulOS

139. OS/400

OS/400

140. Oasis

Oasis

141. ParallelKnoppix

ParallelKnoppix

142. Kylin

Kylin

143. PSOS

PSOS

144. Alpha OS

Alpha OS

145. OpenServer

OpenServer

146. AIX

AIX

147. CP/M

CP/M

148. GEOS

GEOS

149. IRIX

IRIX

150. NeXTSTEP (foundation for OS X)

NeXTSTEP (foundation for OS X)

151. QNX

QNX

152. Yggdrasil Linux

Yggdrasil Linux

153. OS-C

OS-C

154. Power Desktop

Power Desktop

155. A/UX

A/UX

156. Amstrad

Amstrad

157. BSDi

BSDi

158. Beowulf

Beowulf

159. Chorus

Chorus

160. DIGITAL UNIX

DIGITAL UNIX

161. Darwin

Darwin

162. L13Plus

L13Plus

163. LAN Manager

LAN Manager

164. LDOS

LDOS

165. LNX-BBC

LNX-BBC

166. IRTS

IRTS

167. Lisa OS

Lisa OS

168. Novell DOS

Novell DOS

169. SCO OpenServer

SCO OpenServer

170. SymbOS

SymbOS

171. TRS-DOS

TRS-DOS

172. CDOS

CDOS

173. CMW+ (SCO)

CMW+ (SCO)

174. COBRA

COBRA

175. CONSENSYS

CONSENSYS

176. CP/K

CP/K

177. CP/NET

CP/NET

178. CP/Z

CP/Z

179. CPF (Control Program Facility)

CPF (Control Program Facility)

180. CSOC

CSOC

181. CTOS

CTOS

182. CTSS

CTSS

183. CX/SX

CX/SX

184. Calmira

Calmira

185. Cefarix

Cefarix

186. Chaos

Chaos

187. ChibiOS

ChibiOS

188. Chippewa OS

Chippewa OS

189. Cinder OS

Cinder OS

190. Cisco IOS

Cisco IOS

191. ClearOS

ClearOS

192. Clicker32

Clicker32

193. Contiki

Contiki

194. Cosy

Cosy

195. Cronus

Cronus

196. Cygnus

Cygnus

197. DAC

DAC

198. DCP

DCP

199. DELL UNIX

DELL UNIX

200. DEMOS

DEMOS

201. DESKWORK

DESKWORK

202. DG/UX

DG/UX

203. DK/DOS

DK/DOS

204. DLD

DLD

205. DNIX

DNIX

206. DOS

DOS

207. DOS 50

DOS 50

208. DOS2

DOS2

209. DR-DOS

DR-DOS

210. DTOS

DTOS

211. DVIX

DVIX

212. DYNIX Unix (Sequent)

DYNIX Unix (Sequent)

213. Degenerate OS

Degenerate OS

214. Delitalk

Delitalk

215. Deming OS

Deming OS

216. Domain OS

Domain OS

217. Dosket

Dosket

218. Draco Linux

Draco Linux

219. Dragon Linux

Dragon Linux

220. Drops

Drops

221. Drywell OS

Drywell OS

222. ECL-3211

ECL-3211

223. EGOS

EGOS

224. ELKS

ELKS

225. EOS

EOS

226. EP/IX

EP/IX

227. EPOC

EPOC

228. ERIKA

ERIKA

229. EROS

EROS

230. ESER

ESER

231. ESIX

ESIX

232. ESKO

ESKO

233. EduOS

EduOS

234. Elate

Elate

235. Elysium

Elysium

236. EuNIX

EuNIX

237. Eumel

Eumel

238. ExOS

ExOS

239. Exopc

Exopc

240. Express

Express

241. FDOS

FDOS

242. FLP-80 DOS

FLP-80 DOS

243. FMS

FMS

244. Famos

Famos

245. Fiasco

Fiasco

246. Flamethrower

Flamethrower

247. FlashOS

FlashOS

248. FlexOS

FlexOS

249. FlingOS

FlingOS

250. Flux

Flux

251. Flux-Fluke-Flask

Flux-Fluke-Flask

252. FoX Desktop

FoX Desktop

253. Forth

Forth

254. FortiOS

FortiOS

255. FreeDOWS

FreeDOWS

256. FreeVMS

FreeVMS

257. Frenzy

Frenzy

258. FunatixOS

FunatixOS

259. FxOS

FxOS

260. GCOS

GCOS

261. GECOS

GECOS

262. GEORGE

GEORGE

263. GM OS

GM OS

264. GNU Hurd

GNU Hurd

265. GNUstep

GNUstep

266. GazOS

GazOS

267. GeekOS

GeekOS

268. Gemini Nucleus

Gemini Nucleus

269. Genera

Genera

270. Go

Go

271. Goah

Goah

272. Gould OS

Gould OS

273. Grasshopper

Grasshopper

274. HA-MSP

HA-MSP

275. HES

HES

276. HOPE

HOPE

277. HP-87 OS

HP-87 OS

278. HP-UX

HP-UX

279. HP-UX from HP

HP-UX from HP

280. HT-11

HT-11

281. Hactar

Hactar

282. Helios

Helios

283. Hive

Hive

284. Hurd

Hurd

285. Hurricane

Hurricane

286. HydrixOS

HydrixOS

287. IBM PC-DOS

IBM PC-DOS

288. IBSYS

IBSYS

289. ICL Unix

ICL Unix

290. INMOS

INMOS

291. INTEGRITY RTOS

INTEGRITY RTOS

292. ISC (Interactive)

ISC (Interactive)

293. ISSL

ISSL

294. ITRON

ITRON

295. Icaros Desktop

Icaros Desktop

296. Idris from Whitesmiths

Idris from Whitesmiths

297. Immunix

Immunix

298. Inferno

Inferno

299. Iridium OS

Iridium OS

300. JOS

JOS