[michaelmure]

A practical example of a op-based Merkle-DAG CRDT is (I believe) git-bug[1]. Some doc here[2].

I originally wrote something akin to an op-based CRDT and enforcing a purely linear series of commits in git's DAG, but eventually found that it doesn't really work in a multiplayer configuration. Eventually, I realized that I could instead have a real DAG to capture the concurrent editions, with "empty commits" as DAG merge operation.

The result is more or less what is described in that article, with some nice properties:

- written in go, I now have a generic implementation[3][4] that, given a set of operation, can easily support many practical use cases (bug tracker issue is the first, kanban and pull-requests coming).

- git itself is taking care of the storage and the synchronization with peers (aka git remotes). I get the full set of upsides described in the article.

- unfinished for now, but I can leverage some git construct to crypto sign each interaction with the data structure, to prove authenticity and later construct a proper access right system (who can edit a comment, who has admin right ...).

- additionally to the DAG structure, I also have lamport clock to give an order between each independent DAGs (last edited bug ...). They are also used as a help to compute the final order within a DAG if there is ambiguity (concurrent editing).

I'm much more an engineer than a researcher, so it'd be awesome to have the opinion of the community and especially iamwil, hecturchi or lxpz.

[1]: https://github.com/MichaelMure/git-bug [2]: https://github.com/MichaelMure/git-bug/blob/master/doc/model... [3]: https://github.com/MichaelMure/git-bug/blob/master/entity/da... [4]: https://github.com/MichaelMure/git-bug/tree/master/entity/da...