For anyone wondering what the heck is Mastodon, it's a micro-blogging platform similar to Twitter. The big difference is it's decentralized and open source. Many servers exist, and when you join a server (called instance), you can follow people from other instances.
Mastodon is also part of the fediverse
, or federated universe, shared by other open source social media platforms such as Diaspora*, GNU Social, Friendica, PeerTube and many others; they share the same communication protocol so someone on Friendica can potentially communicate seamlessly to somebody else on a different platform. For example, I could find freecad-heini-1 profile on Peertube.mastodon.host and follow him, the next time he publishes a video on Peertube, I'll get notified on Mastodon (I think).
Mastodon is the fastest growing open source social media platform: it has over 1,860,000 users and currently gaining 25,000 new users weekly.
Mastodon.social is one of the biggest instances, with 300,000 users and the activity there (shown in a local timeline) is overwhelming. I joined the fosstodon.org
instance, which as its name suggests, is geared toward FOSS (free and open source software) and has only 2,000 users.
See you guys there! Or not.