Jonathan Edwards gives a demo of subtextual (17 minute stream), a programming language that is very close to the type of graph-structured language that I've been imagining for the Tablet PC. The main difference is that he's figured out how to cleanly allow his language to have cycles, which stymied me. He has a manifesto with which I am in complete agreement, although I'd probably emphasize different things. For instance, he seems to emphasize “copying” while I'd probably emphasize “linking” and he seems comfortable using a tree-like representation of the program while free positioning in X,Y space is an important part of the experience I envision (hinted at in the DAGDraw image).