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Spacewar!, 1961, Martin Graetz, Stephen Russell, and Wayne Wiitanen, computer program for DEC PDP-1 computer. Photo credit: Joi Ito, http://joi.ito.com, CC-BY.
Trigger Happy, 1998, Jon Thomson and Alison Craighead, computer program written in Macromedia Director, the predecessor to Flash, used by permission of the artist. Screen shot taken November 17, 2008, http://www.thomson-craighead.net/docs/thap.html/