vit.am is a Fediverse instance that uses the ActivityPub protocol. In other words, users at this host can communicate with people that use software like Mastodon, Pleroma, Friendica, etc. all around the world.
This server runs the snac software and there is no automatic sign-up process.
I've been on the fence about hosting my own #fediverse account for a while now, mainly because of the insane hardware requirements.
I've considered pleroma/akkoma for a while, but i don't know the first thing about elixir and their docs are not the most clear. I've been really tempted by #GoToSocial, but #snac's easy install & general simplicity made me take the plunge.