Mumble is an open-source, low-latency, high quality voice chat
Distributed instant messaging system for developers
The Free & Popular FLARUM Web Software in a Complete Virtual Machine
Free, portable and lightweight Internet Relay Chat server
PHP driven chat forum
Atom chat room nestjs+vue full stack chat room
Chat over SSH
ChatSecure is a free and open source encrypted chat client for iOS
Self-hosted chat app for small teams
The IRC's Talking Robot
It can add a chat room with Flash & HTML 5 Client into SMF.
Secure chat and conferencing protocol
The original Xivio.com World Server Core
PHP Web Chat System utilizing Websockets HTML5 Technology
A Java RMI base messenger which works on LAN
Mossawir Lan Messenge 3, Sever less Peer 2 Peer Lan messenger
Mult-platform chat for LAN. No server required