Mastodon has become super stable. It is the place to go.

Absolutely - though some people find it too bare bones. It's designed to be a bit of an anti-Twitter, after all.

Those looking for something more flashy might be interested in checking out, for example, Firefish. The Firefish site also includes a neat "Fediverse software comparison", which lists popular federated services and some of the features they currently have. Personally I prefer the stripped down approach of Mastodon, but reasonable people might disagree. :)

Is Firefish the same thing as Calckey?