Self hosted messaging chat

Matrix
Matrix is an open network for secure and decentralized communication. Users from every Matrix homeserver can chat with users from all other Matrix servers. You can even use bridges (also called Matrix appservices) to communicate with users outside of Matrix, like a community on Discord.
Self-hosted servers:
- https://conduit.rs/ (language Rust - beta)
- https://github.com/element-hq/dendrite (language Go - beta)
- https://hub.docker.com/r/matrixdotorg/synapse (too Heavy)
- https://github.com/matrix-construct/tuwunel (conduwuit successor)
Protocol: Matrix
Client: Element