Sharkord - an open-source self-hostable Discord alternative with voice, video, and real-time messaging.

Came across this on the r/selfhosted community. Still very much in the alpha stages, but it's already got a Docker image you can try out for yourself, or try out the demo server.

Tried it earlier today, couldn't get the voice/video chat to work right away on my self-hosted setup but the real-time chat was very snappy. Looks promising.