SmoothDraw[1] is what Kahn Academy uses, but it lacks those features you mention. Milton[2] is an open source stroke based application, so you get infinite can

SmoothDraw[1] is what Kahn Academy uses, but it lacks those features you mention. Milton[2] is an open source stroke based application, so you get infinite canvas and infinite zoom. Neither are network-based though and it's tough to beat a physical whiteboard. [1] http://www.smoothdraw.com/sd http://www.smoothdraw.com/sd [2] https://github.com/serge-rgb/milton https://github.com/serge-rgb/milton