hypercore

Isn't this what Hypercore[0] is? But distributed? It's a append-only log, and then there's higher order abstractions built on top of this log. Hyperstore is a key value store that uses an append only log, hyperdrive is a filesystem, etc... [0]: https://github.com/holepunchto/hypercore

There is the Dat installer for installing Android applications (https://github.com/staltz/dat-installer/). Also a bunch of zines and music albums are shared over DAT. There is hypercore (https://github.com/mafintosh/hypercore), a distributed append only log library. Rotonde, a DAT based social network (https://github.com/Rotonde) Secure Scuttlebutt now supports dat attachments... Cabal (https://github.com/cabal-club/cabal-cli), a chat program.

Dat is mentioned in the OP article[0]: the authors have built on top of hypercore[1] (part of the Dat project) to make Hypermerge[2] [0] https://www.inkandswitch.com/local-first.html#crdts [1] https://github.com/mafintosh/hypercore [2] https://github.com/automerge/hypermerge

The hypercore[1] signed append-only log which is the heart of the Dat protocol[2] is an implementation of very similar ideas. The data structure consists of an append-only log, a Merkle tree (stored in the "inorder storage layout" described in Appendix B), and signatures for each of the root hashes of the Merkle tree. The public key ("read key") of the key pair which is used to sign the tree roots can be used as a unique identifier of the contents of the log, eg. for looking up peers in a DHT which can serve the contents. It features a replication protocol which is similar to the one described in the article (if you squint hard enough). A fantastic in-depth explainer of the data structure and the protocol is available at [3]. The current implementation is in Node.js, but a Rust port is under way. [4] [1]: https://github.com/mafintosh/hype

Yes, Dat's core data structure is an append-only log that is designed for extremely fast real-time replication. http://github.com/mafintosh/hypercore If you use Dat through its command-line app, you get real-time updates to the files shared using it.

The way this is done in dat (via the hypercore module) is that the share key is a publickey, the merkle tree is signed with the private key. Updates can stream in on the log, and only the keys in the tree that have changed need updating. The history is stored in the log so you can retrieve any previous version. https://github.com/mafintosh/hypercore