See Alto Mail
The desktop computer from Xerox that pioneered the mouse/icon/desktop environment. Developed at the Palo Alto Research Center (PARC) in 1973, it was the progenitor of Xerox's Star and Apple's Lisa and Mac. At PARC, Lawrence Tesler and Tim Mott helped design the Alto's user interface, and Tesler later went to work for Apple.
Alto specs were 128K RAM, 2.5MB hard drive, 608x808 resolution and Ethernet. By 1979, about 1,000 units were in use. See Xerox Star
The first graphical user interface created for business was working more than a decade before the Macintosh debuted in 1984. (Image courtesy of Palo Alto Research Center.)