Yeah, it has been hard to miss it (see e.g. Should I join Mastodon? A scientists’ guide to Twitter’s rival). Twitter is experiencing some turbulence and Mastodon has become a very attractive, open source, community-driven, inclusive alternative. It’s been around since 2016 and there is some research literature about it already. I got my account in 2018, but did not start actively using it until earlier this year.