ot.js

https://github.com/josephg/sharejs https://github.com/FirebaseExtended/firepad https://github.com/Operational-Transformation/ot.js https://github.com/ottypes/docs Really nice demo: https://operational-transformation.github.io

This single file shows the entire set of OT transformations (retain, insert, delete): https://github.com/Operational-Transformation/ot.js/blob/mas... and this is a good post outlining the basics of OT, from the creator of CodeMirror: https://marijnhaverbeke.nl/blog/collaborative-editing-cm.htm...

Thanks! Operational transformation is the same technology that powers Google Docs. It's been studied in academia for real-time collaboration since the 1990s and has eventual consistency guarantees. See the Wikipedia article: https://en.wikipedia.org/wiki/Operational_transformation The Rust operational-transform library was not written by me, but it's listed on crates.io by spebern, and it's worked wonderfully so far. It seems to be a very close port of ot.js (https://github.com/Operational-Transformation/ot.js). The text transformation algorithm isn't very complicated (<700 SLOC including tests), but there's probably room for optimization!

I was able to get real-time collaborative text editing to work on one of my side projects by combining quill.js[1], ot.js[2], and firebase[3]. This was a few years ago when there weren't any fully open-source options. I'm in the process of switching out firebase for an elixir/phoenix backend[4]. I'm really glad for this article because it captures the exact feelings that I have. [1] https://quilljs.com/ [2] https://github.com/Operational-Transformation/ot.js/ [3] https://firebase.google.com/ [4] https://github.com/phoenixframework/phoenix

It uses a theory called Operational Transformation [1] which is roughly the base for most collaborative tools like google docs. My first attempt was using a library called ot.js [2], I changed it to support an async db since it only supported a in-memory store and I adapted to use mongodb. The experiment is in [3] and it has some bugs still. Then I found out the guys at firebase adapted ot.js client side to work with their own db, and created something called Firepad [4]. So, I used that instead which was more stable and I added auth and authn. [1]: https://en.wikipedia.org/wiki/Operational_transformation [2]: https://github.com/Operational-Transformation/ot.js/ [3]: http://github.com/auth0/mdocs and http://mdocs.io [4]: http://www.firepad.io/

You should also checkout ot.js: https://github.com/Operational-Transformation/ot.js/ They have a nice visualization of OT here: http://operational-transformation.github.io/visualization.ht...

We built it as a Firebase app, but we're releasing it as open source and are looking forward to seeing what the community does with it. :-) All of the OT work happens client-side, so it's certainly possible to adapt it to other backends. Additionally, a lot of the OT code is based on ot.js[1], a fantastic open source OT implementation by Tim Baumann. He has a node.js backend as well as Haskell and Python. Of course then you have to run the server code somewhere and figure out how to persist the documents, etc. :-) Definitely worth checking out though. 1. https://github.com/Operational-Transformation/ot.js/