GNUnet

GNUnet: "GNUnet is a framework for secure peer-to-peer networking that does not use any centralized or otherwise trusted services. A first service implemented on top of the networking layer allows anonymous censorship-resistant file-sharing. GNUnet uses a simple, excess-based economic model to allocate resources. Peers in GNUnet monitor each others behavior with respect to resource usage; peers that contribute to the network are rewarded with better service."