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 focused on privacy and security for communication and file sharing, while Riot.im (now known as Element) is a real-time messaging app that supports end-to-end encryption and integrates with various services, making it more user-friendly for general communication.