Exactly what gatob said. Lemmy is the platform that all instances (Lemmy.world, lemmy.ml, etc) connect to.

All apps work with all instances. There’s jerboa, connect, wefwef (soon renamed to voyager thank god), liftoff, with more coming soon (boost & sync of reddit fame)

While true, it sounds like communities from instances that un-federate should be avoided. More users are on other instances so the beehaw ones should be left to die in obscurity

You can just search for something like Android and it’ll show all the communities including the instance it’s on and join; you don’t need multiple logins.

The app I use, wefwef, also can view all communities in the feed along with your subscribed or just local instance communities. I’d assume liftoff is similar but I’ve never used it.

You only need to sign up for one instance. What app are you using or is it the browser?