[Reinmar]

Thank god I didn't question what josephg wrote regarding the text-based OT :D

I'm actually part of the team that built real-time collaboration for CKEditor 5. As the article says, we use a tree-structured representation for rich-text data and decided (many years ago) to go with OT. My guess always was that GDocs also uses a tree structure as the internal data model or that at least Google Wave did. I think I based this on a comment from a Google employee who summed up their OT implementation as hard to stabilize, even over many years.

I know it's possible to kind of represent rich-text data in form of a linear structure. This makes the implementation of the OT much much simpler. But then the editor itself becomes much more limited or you need to combine multiple instances of its model to represent more complex data. E.g., AFAIK Quill (mentioned in the other comment) does not offer stable tables implementation. Something that wasn't that big of a deal for us.

[lewisjoe]

Google Docs actually uses a flat array representation of the whole document. Tables/lists and other structures are encoded using control-characters in the plain string. This makes index calculations for OT a bit easier.

How do I know? I work on Zoho Writer - a google docs alternative and we use the same technique :)

Glad to meet you. Huge fan of CKeditor's modular architecture of the editor. Making something with that level of customization and supporting realtime collaboration is not an easy feat at all!

What are your thoughts on CRDT generally? Will CKeditor ever look into adopting CRDTs in the future?