RetroShare is open source software for encrypted filesharing, serverless email, instant messaging, online chat, and BBS, based on a friend-to-friend network built on GNU Privacy Guard (GPG). Developed by DrBob
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.