CADtron is a gesture-based 2D CAD prototype exploring the idea that: 1. Precision mouse clicking is annoying, so 2. a CAD tool built on pen-input / gestures might feel faster, more fluid, and more fun

Goddamn, that's smart. When he said "it still works when you take off your glasses and are half drunk," I was sold. :) What I love about this is that it abandons the naive analogy. People are used to doing drawings, so let's do a digital drawing, was the original idea. Then they abandoned the naive 2D drawing analogy for a projection of a 3D diagram, and it got better. He has abandoned the naive analogy that the pen creates marks on the drawing, and decided it is a 3D input tool, two dimensions of location, one of press. Then invented a language that can be used in the projection. Imagine you allowed the user to draw lines and rotate view at the same time. Touch the pen to the tablet, then spin the view. Boom. Arc, or circle. Inspiring stuff.