Psyced - This is psyced, a scalable multi-protocol multi-casting chat, messaging and social server solution...
LimeWire - LimeWire is a free peer-to-peer file sharing platform that is available to use on Windows, Mac OS and Solaris platforms.
Jitsi - Open-source video calling and chat platform.
eMule - eMule is a free peer-to-peer file sharing application for Microsoft Windows.
MagicPad - Free, simple, and private, offline text encryption suite.
Phex - Phex is a peer-to-peer file sharing client for the Gnutella network.