I've seen a demonstration of zigzag implementing a family tree, I was impressed by its speed and fluidity as well as its ease of use. There is some background a

I've seen a demonstration of zigzag implementing a family tree, I was impressed by its speed and fluidity as well as its ease of use. There is some background and an image of the system here http://crca-archive.ucsd.edu/view_event.php?id=60 http://crca-archive.ucsd.edu/view_event.php?id=60