Cloud based code environments are starting to merge this. Github Code Spaces for one are starting this. I don't know if they use Operational Transaction (OT) or Conflict-Free Replicated Data Types (CRDT) but they are repo backed. I assume it is just using Github diffing tools in the repos and maybe OT/CRDT in live sessions over WebRTC or similar.
Much of real-time collaboration goes back to networking and real-time networking used in distributed multi-user systems like games, where simulations need to sync on a server. In games though, Dead Reckoning [2] is used as well as interpolation and extrapolation in prediction, much of it can be slightly different for instance with physics/effect, but messages that are important to all like scores or game start/end are reliably synced and determined on the server.
I wonder if there is a way to describe change sets as a mathematical curve and achieve something like the rewind-ability within Planetary Annihilation https://www.forrestthewoods.com/blog/tech_of_planetary_annih... which seems to be an smoother alternative to dead-reckoning that bakes the history into it a bit better.
Much of real-time collaboration goes back to networking and real-time networking used in distributed multi-user systems like games, where simulations need to sync on a server. In games though, Dead Reckoning [2] is used as well as interpolation and extrapolation in prediction, much of it can be slightly different for instance with physics/effect, but messages that are important to all like scores or game start/end are reliably synced and determined on the server.
[1] https://visualstudio.microsoft.com/services/github-codespace...
[2] https://www.gamasutra.com/view/feature/131638/dead_reckoning...