Holochain is a distributed version control system for the development of social applications / protocols. Imagine if Uber or Airbnb were just protocols, able to be used without the company in the middle - in a fully peer to peer context. You could evolve and improve the rules together with others peers, and start playing new economic and social ‘games’ without any central authority being able to block you from experimenting/doing so.

Holochain’s novelty lies in its use of DHT’s to create, store and retrieve data. Like Git source chains, it then uses cryptography to guarantee data integrity in this distributed application context. You’re basically agreeing in advance on which functions to use. Instead of using proprietary functions that are kept secret behind a firewall or limited through an API, Holochain allows you to create and use apps that directly enforce and verify open rules in a 100% distributed peer to peer way. To the best of my knowledge this sort of system hasn’t been seen or invented before.

Thy have great descriptions on their website:

[from https://holo.host/faq/]

“Holochain maintains data integrity without the need for global consensus. It uses an agent-centric approach, combining ideas from BitTorrent and Git, along with cryptographic signatures, peer validation, and gossip.

An overview:

- hApps have validation rules.

- Agents have their own local, tamper-resistant hash-chains recording their actions, built upon hApp rules.

- Each hash-chain entry is cryptographically signed (multi-party actions, like transactions, are mutually countersigned).

- Data is shared to random peers who validate it.

- Validators gossip to share good data, warn against bad data, and blacklist bad actors.“

Their code is free software, available on Github here: https://github.com/holochain