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
Matrix.org offers a decentralized and highly customizable communication platform that supports various protocols, making it ideal for diverse use cases. In contrast, Openfire is a robust XMPP server, well-suited for real-time chat applications in enterprise settings, but may lack the modern features and flexibility that Matrix provides.