Microsoft operating systems

Microsoft operating systems

• 
  1. MS-DOS
  
• 
  2. Windows
  

Windows 2.0 (1987)

Windows 3.x (1990, 1992)

Windows 95 (1995)

Windows 98 (1998)

Windows 2000 (2000)

Windows ME (2000)

Windows XP (2001)

Windows Vista (2006)

Windows 7 (2009)

Windows 8 (2012)

Windows 8.1 (2013)

Windows 10 (2015)

Windows 10 (Anniversary Update) (2016)

• 
  3. Windows NT
  
• 
  4. Windows CE
  
• 
  5. Windows Phone
  

Windows Phone 8 (2012)

Windows Phone 8.1 (2014)

Windows Mobile 10 (2015)

• 
  6. Xbox gaming
  
• 
  7. OS/2
  
• 
  8. Other operating systems
  

1. 
   Microsoft Linux distributions
   
2. 
   MIDAS
   
3. 
   Singularity
   
4. 
   Xenix
   
5. 
   Zune
   

(/ˌɛmɛsˈdɒs/ em-es-doss; acronym for Microsoft Disk Operating System) is a discontinued operating system forx86-based personal computers mostly developed by Microsoft. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s and the early 1990s, when it was gradually superseded by operating systems offering a graphical user interface (GUI), in various generations of the graphical Microsoft Windows operating system by Microsoft Corporation.

MS-DOS resulted from a request in 1981 by IBM for an operating system to use in its IBM PC range of personal computers. Microsoft quickly bought the rights to 86-DOS from Seattle Computer Products, and began work on modifying it to meet IBM's specification. IBM licensed and released it in August 1981 as PC DOS 1.0 for use in their PCs. Although MS-DOS and PC DOS were initially developed in parallel by Microsoft and IBM, in subsequent years the two products diverged, with recognizable differences in compatibility, syntax, and capabilities.

During its life, several competing products were released for the x86 platform, and MS-DOS went through eight versions, until development ceased in 2000.

When IBM introduced the IBM PC, built with the Intel 8088 microprocessor, they needed an operating system.

IBM again approached Bill Gates. Gates in turn approached Seattle Computer Products. There, programmer Tim Paterson had developed a variant of CP/M-80, intended as an internal product for testing SCP's new 16-bit Intel 8086 CPU card for the S-100 bus. The system was initially named QDOS (Quick and Dirty Operating System), before being made commercially available as 86-DOS. Microsoft purchased 86-DOS, allegedly for $50,000. This became Microsoft Disk Operating System, MS-DOS, introduced in 1981.

Within a year Microsoft licensed MS-DOS to over 70 other companies, which supplied the operating system for their own hardware, sometimes under their own names. Microsoft later required the use of the MS-DOS name, with the exception of the IBM variant. IBM continued to develop their version, PC DOS, for the IBM PC. Digital Research became aware that an operating system similar to CP/M was being sold by IBM (under the same name that IBM insisted upon for CP/M), and threatened legal action. IBM responded by offering an agreement: they would give PC consumers a choice of PC DOS or CP/M-86, Kildall's 8086 version. Side-by-side, CP/M cost almost $200 more than PC DOS, and sales were low. CP/M faded, with MS-DOS and PC DOS becoming the marketed operating system for PCs and PC compatibles.

Microsoft originally sold MS-DOS only to original equipment manufacturers (OEMs). One major reason for this was that not all early PCs were 100% IBM PC compatible. 

The FreeDOS project began 26 June 1994, when Microsoft announced it would no longer sell or support MS-DOS. Jim Hall then posted a manifesto proposing the development of an open-source replacement. Within a few weeks, other programmers including Pat Villani and Tim Norman joined the project. A kernel, the COMMAND.COM command line interpreter (shell) and core utilities were created by pooling code they had written or found available. There were several official pre-release distributions of FreeDOS before the FreeDOS 1.0 distribution was released on 3 September 2006. Made available under the GNU General Public License (GPL), FreeDOS does not require license fees or royalties.
2. Windows

Microsoft introduced an operating environment named Windows on November 20, 1985, as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces (GUIs). Microsoft Windows came to dominate the world's personal computer (PC) market with over 90% market share, overtaking Mac OS, which had been introduced in 1984. Apple came to see Windows as an unfair encroachment on their innovation in GUI development as implemented on products such as the Lisa and Macintosh (eventually settled in court in Microsoft's favour in 1993). On PCs, Windows is still the most popular operating system. However, in 2014, Microsoft admitted losing the majority of the overall operating system market to Android, because of the massive growth in sales of Android smartphones. In 2014, the number of Windows devices sold were less than 25% of Android devices sold. This comparison, however, may not be fully relevant as the two operating systems traditionally targeted different platforms.

As of September 2016, the most recent version of Windows for PCs, tablets, smartphones and embedded devices is Windows 10. The most recent version for server computers is Windows Server 2016. A specialized version of Windows runs on the Xbox One game console.

Windows Server 2016 is a server operating system developed by Microsoft as part of the Windows NT family of operating systems, developed concurrently with Windows 10. The first early preview version (Technical Preview) became available on October 1, 2014 together with the first technical preview of System Center. Unlike previous Windows Server versions, which were released simultaneously with the client operating system, Windows Server 2016 was released on September 26, 2016 at Microsoft's Ignite conference and became generally available on October 12, 2016.
3. Windows NT

Started as a family of operating system with Windows NT 3.1, an operating system for server computers and workstations. It now consists of three operating system subfamilies that are released almost at the same time and share the same kernel. It is almost impossible for someone unfamiliar with the subject to identify the members of this family by name because they do not adhere to any specific rule; e.g. Windows Vista, Windows 7, Windows 8/8.1 and Windows RT are members of this family but Windows 3.1 is not.

4. Windows CE

Windows Embedded Compact was formerly known as Windows CE. According to Microsoft, "CE" is not an explicit acronym for anything, although it implies a number of notions that Windows developers had in mind, such as "compact", "connectable", "compatible", "companion" and "efficient". The name changed once in 2006, with the release of Windows Embedded CE 6.0, and again in 2011, with the release of Windows Embedded Compact 7.

It is optimized for devices that have minimal memory; a Windows CE kernel may run with one megabyte of memory. Devices are often configured without disk storage, and may be configured as a "closed" system that does not allow for end-user extension (for instance, it can be burned into ROM). Windows CE conforms to the definition of a real-time operating system, with a deterministic interrupt latency. From Version 3 and onward, the system supports 256 priority levels and uses priority inheritance for dealing with priority inversion. The fundamental unit of execution is the thread. This helps to simplify the interface and improve execution time.

Microsoft's promotion of the Metro design language

is a series of computer operating systems, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2", because it was introduced as part of the same generation change release as IBM's "Personal System/2 (PS/2)" line of second-generation personal computers. The first version of OS/2 was released in December 1987 and newer versions were released until December 2001.

OS/2 was intended as a protected mode successor of PC DOS. Notably, basic system calls were modelled after MS-DOS calls; their names even started with "Dos" and it was possible to create "Family Mode" applications: text mode applications that could work on both systems. Because of this heritage, OS/2 shares similarities with Unix, Xenix, and Windows NT in many ways.

IBM discontinued its support for OS/2 on 31 December 2006. Since then, it has been updated, maintained and marketed under the name eComStation. In 2015 it was announced that a new OEM distribution of OS/2 would be released that was to be called ArcaOS.

In the past, Microsoft has strategically excluded any support for Linux due to it being a competitor operating system. However, as its partners have gradually embraced multiple technologies, the partnership became inevitable.

The Zune hardware players were discontinued in October 2011. In June 2012, Microsoft announced plans to discontinue all "Zune" services; instead Microsoft would distribute its digital media content and services under the Xbox Music and Xbox Video brands available on its line of products including Windows 8 PCs and tablets, Xbox 360 game console, and Windows Phone smart phones.