A New Kind of Instant Messaging
Mumble is an open-source, low-latency, high quality voice chat
The first messaging platform operating without user identifiers
An alternative Discord client with voice support made with C++ and GTK
A glossy Matrix collaboration client for the web
Private messenger for Windows, Mac, and Linux
You can message and share files inside your intranet without a server.
Cerberus Content Management System
Chat Messenger. E-Mail-Client. Websearch. Filetransfer.
Low-latency, high quality voice chat for gamers
A portable peer to peer voice-chat/walkie-talkie.
Darkbot is an AI robot for IRC, especially useful for help channels.
[WARNING] Project has moved to http://github.com/Retroshare/Retroshare
A small (ish) messaging server for anything you can think of
Microsoft SMB protocol plugin for Miranda IM.
The IRC's Talking Robot
Up to date MUD client evolved from the original MudMaster
Chat Messenger - Open Source Social Network - Online Chess Game
An intranet chat application that does not require a server.