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
RetroShare is a decentralized platform that emphasizes secure communication and file sharing with built-in chat features, while MLDonkey focuses on cross-network file sharing with extensive configurability and plugin support. Both have unique advantages but cater to different user needs.