Sketchpad

The starting line. Ivan Sutherland built Sketchpad for his 1963 MIT thesis on the TX-2 computer, and a light pen let him draw straight onto the screen. Before it, a computer turned out plots and printouts; with it, a person could draw a shape, grab it and change it while the machine kept up. That shift from batch output to live interaction is the leap. Sketchpad pioneered rubber-banding, zooming and drawing built from objects rather than loose marks, ideas that run through every design tool since, and it was the first interactive graphics program to work with geometric constraints. Computer-aided design arrived more or less fully formed in one project.