I wish the twitter dissidents would know about the fediverse and not just "mastodon". Mastodon is 1 little piece of a huge network, the fediverse. There are plenty of platforms to choose from. I personally recommend Friendica. Our instance social.trom.tf has a custom made theme and is pretty much working 24h without issues. It can even connect with Twitter and you can post on Twitter too, follow people from Twitter, reply, get notifications when someone comments on your tweets, and so forth.

Also, it works with any Mastodon apps....

So it is a great option/alternative to have.

Therefore, the Fediverse is a network of multiple services. Some are social networks (friendica, pleroma, hubzilla, mastodon, etc.), some video platforms (peertube), some photo sharing (pixelfed). You choose the platform then the instance (server) where you can create an account. Then you are all set. You can connect with anyone from any network and server.

Done.

Welcome!