I wouldn't put Secure Scuttlebut into the same box as the other two. It doesn't actually try to tackle some of the harder problems like huge files/huge director

I wouldn't put Secure Scuttlebut into the same box as the other two. It doesn't actually try to tackle some of the harder problems like huge files/huge directories etc. that they do. SSB is more in the realm of ActivityPub, but more p2p where ActivityPub is federated.