Matrix is an open protocol for real-time communication. It is designed to allow users with accounts at one communications service provider to communicate with users of a different service provider via online chat, Voice over IP, and Videotelephony. Developed by Matrix.org
License: Open Source
The Invisible Internet Project (I2P) is a garlic routing using overlay network and darknet that allows applications to send messages to each other pseudonymously and securely. Uses include anonymous Web surfing, chatting, blogging and file transfers. The software that implements this layer is called an I2P router and a computer running I2P is called an I2P node.
License: Open Source
I2P focuses on providing high levels of anonymity and is primarily designed for hidden services, making it suitable for privacy-focused users. In contrast, Matrix.org offers a decentralized communication protocol that prioritizes interoperability and real-time messaging, catering to developers and organizations looking for secure communication.