If you click on the WhyDRS link at the top there's where the Supa refugees have been. Your login works on both. AKA https://lemmy.whynotdrs.org/

There's some crossover between Fediverse apps, so some posts here can be commented on in Mastodon if you have login over there. And vicee versa.

This is the equivalent of ALL on reddit... https://lemmy.world/ There are buttons at the top to select which i.nstances.

Since the fediverse runs in individual instances, you can have the same account handle on all of them, or different ones, you go to that server and sign up.

A reference for it all is here...this is mostly about Mastodon right now... https://fedi.tips/

The fediverse has its own video sharing at Peertube and there's a photo sharing site at Pixelfed. Both, and others, linked and explained at Fedi.tips.

I'll add more as I think of them.