AMMDI is an open-notebook hypertext writing experiment, authored by Mike Travers aka mtraven. It's a work in progress and some parts are more polished than others. Comments welcome! More.
The nice thing about agent-based modelling is that a child can understand it (this is the basis for Logo). It's a powerful thinking tool, and much more accessible than more mathy formalisms like CCS or category theory. I've built systems like this in the past, such as Behave! (an animal-behvior modelling environment designed for maximum non-technical accessibility). And see Vivarium Project for a more expansive version of the idea of a learning/simulation environment.
This was a system I designed and implemented for an exhibit at the (now defunct) Boston Computer Museum. It was an interesting challenge – can you build something that conveys something about programming but is usable and learnable by tourists with short attention spans?
This was done at the Media Lab and predated Scratch. I don't have a patent on programming with blocks but still feel I deserved a bit more credit for developing the ideas.
The block-programming designs started here also made their way into the BioBike VPL, Enflame, and Vaguely. The source is on Github but it depends on a version of Mac Common Lisp and the Mac OS that has been obsolete for decades.