[williamstein]

I enjoyed reading this paper. I also recently talked with Chris Colbert about his new plans to use a CRDT approach to collaborative editing of Jupyter notebooks. This made me curious again about how CoCalc’s collaborative editing is related to OT and CRDT approaches, so I wrote up a blog post about that just now. http://blog.sagemath.com/2018/10/11/collaborative-editing.ht...

[nused]

Enjoyed reading your thinking around what "Intention preservation" means for CoCalc. I think "Intention" was left open-ended since it was always meant to be defined in the context of a specific application, e.g. image vs text editing would like have different notions of user-intentions and what it means to preserve them.

TP2 has been made into this monster that seems to scare anyone starting to look at OT. You don't need to worry about TP2 with a suitable protocol with a server or fully peer-to-peer, and either solution are simple enough to implement. A fine point is that TP2 and intention-violation are distinct properties: you can easily achieve convergence by serializing the operations through a total order at every site (but your won't have intentions preserved), on the other hand, if you insert 'a' and I insert 'b' at the same location simultaneously, it's reasonable for both results 'ab' or 'ba' to be intention preserved, but without transformations we'd each see a different result (thus divergence).

We've documented plenty of CRDT's performance and correctness issues in that article. I think a bigger app design question I would ask is if you want to "lock-in" your apps internal data model with a consistency-maintenance scheme -- there is real value in separation of concerns (SoC) .