No, xmpp.org is the XMPP Standards Foundation. The Modern XMPP project is a separate initiative.
Well, as separate as can be - I'm heavily involved in the XSF as well. But the XSF is focused on matters of protocols, and it grew increasingly clear to me that we needed a less official space for collaborating on non-protocol issues such as user interfaces.
@hund @liaizon “We also intend to provide a comprehensive set of guidelines for UI and UX design. Developing a client was never just about the protocol. In fact in most cases the protocol is a secondary concern. Having a concrete set of guidelines will help to provide a more uniform user experience between different applications, ensuring they use the same terminology, and provide interoperable feature sets.”
Fosstodon is an English speaking Mastodon instance that is open to anyone who is interested in technology; particularly free & open source software.