Very true! It's not like it defies the laws of physics ... but, it also shows how much effort is needed to get to something with hackpad's usability on the etherpad core: years worth of work from very smart devs.

If collaborative editing were the main focus of what I was working on, I'd say "yay, market opportunity!" But as it is, I just want to be able to plug in (and contribute to) a good open-source option. Which may wind up being Etherpad, but I'd like to do better ...