Mastodon is a free/libre, decentralized micro-blogging platform…like Twitter but better…where anyone can host their own instance with their own moderation.
Aras Pranckevičius (one of the great minds behind the Unity engine) created a Mastodon instance for game developers today:yes:
https://mastodon.gamedev.place/about
So it’s basically like Twitter but with only gamedev-related stuff.