Windows 1.0
Microsoft began developing a graphical user interface (GUI) in 1981. The development of Windows began after Microsoft founder Bill Gates saw a demonstration at COMDEX 1982 of VisiCorp's Visi On, a GUI software suite for IBM PC compatible computers. In 1983 Microsoft learned that Apple's own GUI software—based in part on Xerox PARC technology–was much more sophisticated, and decided that its own product would be different.