We believe that real-time communication is fundamentally broken and fragmented on today's internet. XMPP and SIP tried to solve this, but haven't taken off as they might have done, leaving the internet dominated by closed proprietary islands of communication like WhatsApp, Facebook, Hangouts, etc.

Enter Matrix: a set of pragmatic RESTful HTTP JSON APIs as an open standard, intended to be implemented on a wide range of servers, services and clients, letting developers build messaging and VoIP functionality on top of the Matrix ecosystem rather than adding yet another closed/proprietary solution.

In Matrix, every user runs one or more Matrix clients, which connect through to a Matrix "homeserver" which stores all their personal chat history and user account information - much as a mail client connects through to an IMAP/SMTP server. Just like email, you can either run your own Matrix homeserver, which means you own and control your own communications and history - or you can use one hosted by someone else (e.g. matrix.org) - there is no single point of control or mandatory service provider in Matrix. In fact, there is no single point of control over conversations in Matrix at all - conversation history is a first class citizen, with room state replicated over all participating servers, avoiding single-points of failure or control as you get in XMPP MUCs.

In the end, we hope Matrix will crack the problem of a widely successful open federated platform for communication on the internet, and provide a worthy alternative to the PSTN. You should be able to use your favourite app to communicate via Matrix - and your recipients should be able to reply through the app of their choice!