GUI

Much like the mouse, it was Apple who first brought the concept of a graphical user interface to the mainstream when it introduced the Lisa computer in 1983, soon followed by the Mac in 1984. In an interesting piece of Apple history, Apple was first turned onto the idea of a GUI when Steve Jobs and other Apple executives took a tour of Xerox's Palo Alto Research Center in 1979. Which arch rival did Apple sue in 1988 over the use of the GUI?