Microsoft Windows or Windows is a metafamily of graphical operating systems developed, 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 Embeddedand Windows Phone; these may encompass subfamilies, e.g. Windows Embedded Compact or Windows Server. 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.
"In order for innovation to happen, a bunch of things that aren't happening on closed platforms need to occur. Valve wouldn't exist today without the PC, or Epic, or Zynga, or Google. They all wouldn't have existed without the openness of the platform. "