SelfHostedMastodon

Run your own Mastodon server

https://docs.joinmastodon.org/user/run-your-own/

In Docker https://hub.docker.com/r/tootsuite/mastodon

You can get hosting accounts from MastoHost ( https://masto.host/ ) BUT currently they seem swamped by recent influx of users from Twitter and have closed new accounts.