GNUnet is a free software framework for decentralized, peer-to-peer networking and an official GNU package. Developed by Christian Grothoff
License: Open Source
GNUnet focuses heavily on privacy and decentralization, making it ideal for users who prioritize anonymity, while RetroShare provides a more user-friendly experience with integrated messaging and file sharing functionalities, appealing to those looking for a simpler decentralized communication tool.