I’m not an expert on this, but the fediverse is just a collection of things that can all communicate on a federated standard. It’s just like email, you can use whatever mail provider you want but you can email anyone else using email.

I guess your question is kind of like “are there other emails?” - and yeah, I guess there are other platforms where you can communicate and send messages, but they aren’t email.

I came across a stack overflow recently about how to do something in a jasmine unit test. Someone gave a solution of “I just changed the test to xit(“… and now there are no errors!”