I'm building Kursal for over a year now. All backend is built in Rust for speed and safety.

No central server and no accounts. Peers connect over libp2p [1] and messages go through a Double Ratchet + PQXDH (Signal's protocol), so it's resistant to quantum attacks too.

I experimented with decentralization and encryption, and described it all on a technical paper [2]

All open source, of course, and I'd love having feedback!

[1] https://libp2p.io [2] https://kursal.chat/kursal.pdf