GNUnet is a peer-to-peer framework with focus on providing security. All peer-to-peer messages in the network are confidential and authenticated. The framework provides a transport abstraction layer and can currently encapsulate the network traffic in UDP, TCP, HTTP, HTTPS, or direct 802.11 (WLAN). GNUnet supports accounting to provide contributing nodes with better service. The services built on top of the framework include anonymous file sharing and a virtual network providing IPv4-IPv6 transition via protocol translation over the P2P network.
SaluSafe is an encrypted email, chat, and file storage and sharing system. Your email and files are highly encrypted end-to-end, and cannot be intercepted by any third party. It was built from the ground up for security via strong cryptography, and is not just another security wrapper on top of an existing email solution.
MUTE File Sharing is an anonymous, decentralized search-and-download file sharing system. Several people have described MUTE as the "third generation file sharing network" (From Napster to Gnutella to MUTE, with each generation getting less centralized and more anonymous). MUTE uses algorithms inspired by ant behavior to route all messages, include file transfers, through a mesh network of neighbor connections.
WASTE is a mesh-based workgroup tool that allows for encrypted, private communication between distant parties on the Internet, independent of local network organization. It is RSA secured, and has been heralded as the most secure P2P connection protocol currently in development. WASTE functions as a both a server and a client under *nix, Mac OS X, and Windows, as well as a server only mode under *nix and Windows.
The Enhanced File Crypt/eXtended File Stealth System (EFC/XFSS) makes your uploaded files safe on the server so that no one can read them without knowing a few details to decipher the files. It generates different obfuscated names and encrypted files so no one will know what the original format or name was.
KDX is a powerful cross-platform BBS-style encrypted Internet communications system that provides messaging, news, file and folder transfer, voice chat (Internet Telephone), text chat, remote access, trackers, and more. It uses strong encryption to protect communications for security and privacy. It is useful for groups that need to collaborate on a project via the Internet. It is also very useful for remote administration of a computer. It uses a client/server architecture.