Website: https://matrix.org/
Source Code: https://github.com/element-hq/synapse
Donate: https://www.patreon.com/matrixdotorg, https://liberapay.com/matrixdotorg, https://www.paypal.com/paypalme/matrixdotorg
ΒΆ Description
"Matrix is an open standard and communication protocol for real-time communication. It aims to make real-time communication work seamlessly between different service providers, in the way that standard Simple Mail Transfer Protocol email currently does for store-and-forward email service, by allowing 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. It therefore serves a similar purpose to protocols like XMPP, but is not based on any existing communication protocol."