Neat. It might be interesting to try this with DrScheme, since it can display images inline in the repl.

http://docs.plt-scheme.org/quick/

http://docs.plt-scheme.org/teachpack/image.html

In the same spirit I would recommend that you try section 2.2.4[1] of the SICP textbook using The SICP Picture Language [2] which can be found here [3].

That section is based on the same original paper, and it is very nice to check on the book's explanation using a modern environment such as DrScheme.

[1] http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-15.html...

[2] http://planet.plt-scheme.org/package-source/soegaard/sicp.pl...

[3] http://planet.plt-scheme.org/display.ss?package=sicp.plt&...

Thank you so much! I first encountered this article back in 2004 or 2005. I just remembered it again about a month ago, and have been fruitlessly Googling for it off and on since then. You've really made my day!

And, I just did a quick port to Python: http://gist.github.com/220038

The GIMP has a Scheme-based console that would be pretty suited to this sort of thing.

Reminds me of Esher. Very cool.