This is not unlike Bret Victor's work - http://vimeo.com/36579366 http://vimeo.com/36579366 . Do watch the video, if you have an hour to spare, it's a beautiful

This is not unlike Bret Victor's work - http://vimeo.com/36579366 http://vimeo.com/36579366 . Do watch the video, if you have an hour to spare, it's a beautiful demonstration of "programming by tinkering."