Addictivetips published a tutorial about how to host a chat server with OpenFire on Linux.
How to host a chat server with OpenFire on Linux
OpenFire is a cross-platform, real-time chat server that is based on the XMPP protocol. It's perfect if you're looking to host your own chat server but don’t want to deal with complicated apps like RocketChat, Mattermost, and others.
How to host a chat server with OpenFire on Linux