GNUnet is a free software framework for decentralized, peer-to-peer networking. The framework offers link encryption, peer discovery and resource allocation.

The primary codebase is written in C, but with Freeway there is an effort to produce a compatible version written in Java. GNUnet currently runs on Linux, BSD, Mac OS X, Solaris and Windows.

It is an official part of the GNU project.

Services running on GNUnet

From Wikipedia under the GNU Free Documentation License
Wed Jul 8 06:32:26 2009