GoToSocial is a lightweight ActivityPub server written in Go. Individuals and small groups use it to run their own social network instance and take part in the fediverse. Users follow people, post short or long messages with images, reply, favourite and share, and read a chronological timeline without recommendation algorithms. Safety features include blocking and limiting posts to friends. You install it on your own server as a binary or Docker image, with SQLite or PostgreSQL, and connect with a client app. The documentation describes it as beta software.
GoToSocial is free software under the GNU AGPL v3. A small core team develops it, funded through OpenCollective, Liberapay and grants from NLnet's NGI0 Entrust fund; the code is hosted on Codeberg. There is no central service: the instance operator decides where data is stored, so an organisation can run it in an EU data centre under its own control. Posts federated to other servers are copied there and governed by those operators. Running an instance means handling updates, moderation and backups.