RetroShare is a cross-platform, secured and decentralized communication system. It lets you to securely chat, share photos, videos, and more with family and friends, using OpenPGP to authenticate peers and OpenSSL to encrypt all communication.
ThunderPhant is unusual P2P application. It can excange folder and DB data! It can use to exchange file between friends or between developers! It implement Subversion system and Security with Asymmetric Enc.
An eMule client that is based on the original one, but with a new credit system.