Nothing nearly as big but FOSSY is organized on similar principles.

As a protocol and whole family of tech, I agree XMPP isn’t something to directly recommend. Inviting to my Snikket server or suggesting Quicksy goes much more smoothly.

Ah I didn’t notice those pages were using my old date format. I’ve updated to my new normal year-dayofyear

Yes

Gajim and Dino are both pretty good depending on what you need and what you like. I use Gajim. On mobile check out https://f-droid.org/en/packages/com.cheogram.android/