Nice article. By the way, you may want to watch this course by Hal Abelson and Gerald Jay Sussman (Henderson Escher example): http://ocw.mit.edu/courses/elec

Nice article. By the way, you may want to watch this course by Hal Abelson and Gerald Jay Sussman (Henderson Escher example): http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-001-structure-and-interpretation-of-computer-programs-spring-2005/video-lectures/3a-henderson-escher-example/ http://ocw.mit.edu/courses/electrical-engineering-and-comput... Also, the article reminded me of LOGO.