(1) For the Windows drawing app, see
Windows Ink.
(2) The first program to incorporate a graphical user interface (GUI). Developed by Ivan Sutherland for his PhD thesis in 1963, Sketchpad is considered the first application of 3D computer-aided design (CAD). Its use of "master" and "occurrences" are said to be the forerunner of objects and instances in object-oriented programming. Sutherland received the Turing Award in 1988 for his creation of Sketchpad. See
Turing Award,
GUI and
CAD.