I don't work at zed anymore but I do find it funny that anyone would think that the collaboration features of zed are "tacked on"...
We started building zed in zed using it's collaboration in early 2021. Collaboration has always been part of it's DNA. Nearly everything at zed is written in pairs over collab.
I joined a Zed hackathon at RustConf 2024 where I built the "Open in split" functionality from the file fuzzy picker. A member of the engineering team who was floating around helping folks had us exclusively work through the included collaboration features. It was a great tour of the editor, and did not feel tacked on.
We started building zed in zed using it's collaboration in early 2021. Collaboration has always been part of it's DNA. Nearly everything at zed is written in pairs over collab.