A good idea might be to put a "styles" principle into other vector graphics tools that alter the line style to conform to certain principles. (maybe they do this already, I don't use much vector graphics software myself).
Looks very cool. Worked well in a quick session. Reminds me of Raphael and others.
Shame the license doesn't seem to be clear in what it allows and doesn't. It just has a generic copyright statement, which strictly speaking means you can't do much with it.
I like it, but something is very wrong in Chrome (Dev track, Win7/64)...keyboard commands don't work, shapes stick in the corner, no way to stop drawing lines.