plt-scheme has a wonderful library for "world" programming. It allows you to get user input and makes it relatively easy (although some of the terminology is a

plt-scheme has a wonderful library for "world" programming. It allows you to get user input and makes it relatively easy (although some of the terminology is a little odd) to make things that move/do stuff graphically. http://download.plt-scheme.org/doc/371/html/teachpack/world.html http://download.plt-scheme.org/doc/371/html/teachpack/world....