Microsoft Windows
Microsoft Windows or Windows is a metafamily of graphical operating systemsdeveloped, marketed, and sold by Microsoft. It consists of several families of operating systems, each of which cater to a certain sector of the computing industry. Active Windows families include Windows NT, Windows Embedded and Windows Phone; these may encompass subfamilies, e.g. Windows Embedded Compact (Windows CE) or Windows Server. Defunct Windows families include Windows 9x and Windows Mobile.
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 ingraphical user interfaces (GUIs).[5] Microsoft Windows came to dominate the world'spersonal computer market with over 90% market share, overtaking Mac OS, which had been introduced in 1984. However, it is outsold by Android on smartphones and tablets.
As of April 2014, the most recent versions of Windows for personal computers,smartphones, server computers and embedded devices are respectively Windows 8.1,Windows Phone 8.1, Windows Server 2012 R2 and Windows Embedded 8. A specialized version of Windows runs on the Xbox One game console.
Technical details
The main component of any windowing system is usually called the display server, although alternative denominations such as window server or compositor are also in use. Any application that runs and presents its GUI in a window, is a client of the display server. The display server and its clients communicate with each other over a communications protocol, which is usually called display server protocol, the display server being the mediator between the clients and the user. It receives all the input from the kernel, that the kernel receives from all attached input devices, such as keyboard, pointing devices, or touchscreen and transmits it to the correct client. The display server is also responsible for the output of the clients to the computer monitor. The output of sound is usually not managed by the display server, but the sound volume, is usually handled through GUI applets and it is the display server who decides which applications are on top. A windowing system enables the computer user to work with several programs at the same time. Each program presents its GUI in its own window, which is generally a rectangular area of the screen.
From a programmer's point of view, a windowing system implements graphical primitives. For example: rendering fonts or drawing a line on the screen. It provides an abstraction of the graphics hardware for use by higher-level elements of the graphical interface such as a window manager.[citation needed]
A display server protocol can be network capable or even network transparent, facilitating the implementation of thin clients
