Cas is a user on cybre.space. You can follow them or interact with them if you have an account anywhere in the fediverse.
A great review I just saw of Mastodon:
"It’s like if twitter and tumblr had a baby and the baby was a significantly better, more likeable person than either of its parents."
--https://snailchimera.tumblr.com/post/167487318965
