Doing it properly is just hard. There is also this CRDT craze going around, but in the end I think operational transformation is a more general and flexible solution (CRDT is just a special case of operational transformation). I have been looking at the various solutions in this space for a few years now, and in the last two or three months started implementing my own experimental solution as a database using operational transformation. It doesn't help that operational transformation in the literature is somewhat confused (there are not many papers about it that are actually correct), although in the end it is really simple.