Vector graphics
Wacom Graphire 3
A little bit of meta-circularity: a drawing of the Wacom Graphire 3 used to make the drawing. Not really of Escherian proportion, but I’ve got to start somewhere. 
You may download the SVG file here (23 kb).
SICP foreword illustrated
In the foreword to SICP, Alan J. Perlis wrote: “Pascal is for building pyramids — imposing, breathtaking, static structures built by armies pushing heavy blocks into place. Lisp is for building organisms — imposing, breathtaking, dynamic structures built by squads fitting fluctuating myriads of simpler organisms into place. ”
I decided to make a little drawing out of that. The Pascal part wasn’t too hard, but I didn’t really know what to do with the Lisp part, so I asked René Gabriëls if he had an idea. He did, and his quick hack of that idea ended up in the SVG file (41 kB). Neither of us is completely happy with it yet, but it shouldn’t be overly hard to make those curved stars into some real microbes.
