Graphical User Interfaces

The first interactive computer graphical interface, Sketchpad, was introduced in 1963 by Ivan Sutherland; it was controlled by a light pen (Negroponte 128).²² With Sketchpad, the concept of direct manipulation, which will be dealt with in section 3.3.3,  was born (Brennan 394). Five years later, Doug Engelbart  presented the first computer mouse  to the world (Dix 60; Negroponte 162).²³
In 1970, Xerox  formed the research lab Xerox PARC , where a group of researchers worked on the design of computers and peripherals (Hiltzik xiii).²⁴ Apart from ethernet , laser printers , and other key technologies, the PARC researchers focused on the development of a graphical user interface (Linzmayer 60-61). Xerox's GUI made use of the desktop metaphor since the target group of the workstation was the office (Dix 124; Levy 69-70; Macauly 100-101). However, Xerox failed to be successful in its efforts in this regard (Hiltzik 395-396).²⁵
Another commercial flop was the Lisa , a personal computer with a graphical user interface which Apple Computer introduced two years after the IBM PC (Linzmayer 69-72). It was followed by the Macintosh  one year later (105). The Apple Macintosh made the desktop metaphor famous, since it was the first affordable machine with a graphical user interface (Johnson 16; see also Levy).²⁶
In 1985, Microsoft introduced Windows, a graphical user interface on top of DOS (Ichbiah 208; Tanenbaum 320-321). Being aware of the limitations of this system, Microsoft and IBM developed OS/2 at the end of the 1980s (Tanenbaum 325). However, most users having spent a considerable amount of money on DOS software did not want to change to the new system; as a consequence, OS/2 failed (320-321). Microsoft continued to work on Windows and released Windows 3.0 in 1990 which became a huge commercial success (Ichbiah 265). Still, this was a graphical user interface on top of DOS, translating mouse clicks into DOS commands (Tanenbaum 321). Windows 95, introduced in 1995, came with a reworked user interface, which has hardly changed in Windows 98 and Windows NT 4.0. Windows 2000, a mixture of Windows NT and Windows 98, will be shipped while this paper is written.
The question whether Apple Computer has "stolen" parts of XEROX's GUI or if Microsoft has "stolen" MacOS concepts for Windows are not a matter for this paper.²⁷ The fact that GUIs became the subject of legal proceedings shows that the computer industry recognized the significance of graphical user interfaces at that time. The ease of use of computer systems had become a key factor in the retail of computer systems (Walker 443).