Exactly. I would encourage the author to put this material together as an IPython Notebook (in conjunction with nbviewer). The IPyNB is a wonderful pedagogic tool.

The OA is very interesting. New educational tools and possibilities are always welcome. However, geogebra is widely used for geometrical investigations on computer at least in the UK.

Maybe, as long as the code doesn't confuse children even more. Perhaps a well though GUI could accomplish this more gracefully.