We're finally taking a look at Sketchpad. This program was completed in 1963 as Ivan Sutherland's Ph.D. research. On the surface it looks like a very fancy drawing program. Under the hood it's hiding some impressive new programming techniques. Selected Sources:
http://worrydream.com/refs/Sutherland-Sketchpad.pdf - Sutherland's Sketchpad thesis
https://www.youtube.com/watch?v=495nCzxM9PI - Sketchpad in action
https://www.computerhistory.org/collections/catalog/102738195 - Oral History transcripts