Pleroma

fediverse system. Pleroma is a free and open-source microblogging social networking service. Unlike popular microblogging services such as Twitter or Weibo, Pleroma can be self-hosted and operated by anyone with a server and a web domain, a combination commonly referred to as an instance. Instance administrators can manage their own code of conduct, terms of service, and content moderation policies, allowing users to have more control over the content they view as well as their experience.[2][full citation needed] It was named after the religious concept of pleroma, or the totality of divine powers.[3] The software also implements the ActivityPub protocol, which allows users to communicate and interact with content from other Pleroma instances or any server that is running software that supports ActivityPub (such as Mastodon, Misskey, Pixelfed, etc.), a decentralized network commonly referred to as the Fediverse. https://en.wikipedia.org/wiki/Pleroma_(software)

open-source, written in Elixir