[roca]

The early 90s also had SRC's Vesta file system which had some interesting properties: https://www.hpl.hp.com/techreports/Compaq-DEC/SRC-RR-106.htm... CMU's Gandalf project had some interesting "semantic" version-control features.

However: it's easy to build experimental systems with cool properties. It's really hard to make them appealing in practice when you have to give up simplifying assumptions.

In particular a lot of these systems were not well adapted to managing collections of text files in unknown formats, edited by unknown tools. That made sense for research purposes, since you can't have as many cool properties without understanding the file formats, but it made them substantially less useful in practice, which I think is partly why they didn't get adopted.