LimeWire - LimeWire is a free peer-to-peer file sharing platform that is available to use on Windows, Mac OS and Solaris platforms.
Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.
eMule - eMule is a free peer-to-peer file sharing application for Microsoft Windows.
MyChat - Secure instant messenger for any network
Phex - Phex is a peer-to-peer file sharing client for the Gnutella network.
Ubiq Security - Enable developers to build encryption into apps in minutes