Harold (Hal) Abelson, a professor of Electrical Engineering and Computer Science at MIT, has a longstanding interest in using computation as a conceptual framework in teaching. He has played a key role in fostering MIT institutional educational technology initiativeI, and is a founding director of Creative Commons and Public Knowledge. Hal's book, Turtle Geometry, written with Andrea diSessa in 1981, presented a computational approach to geometry that has been cited as "the first step in a revolutionary change in the entire teaching/learning process."