Demonsaw - Demonsaw is the next leap in the evolution of a free Internet, and the debut of social cryptography.
Gajim - Full featured and easy to use Jabber client
Jitsi - Open-source video calling and chat platform.
CoyIM - CoyIM is a safe and secure chat client.
i2pd (I2P Daemon) - i2pd (I2P Daemon) is a full-featured C++ implementation of I2P client
Empathy - Apps/Empathy - GNOME Wiki!