Ibis is free software for a decentralized federated wikipedia.
We’re running an instance at https://ibis.z7l.eu/.
Although I’m a lousy Wikipedia user, I really like the idea of a federated wiki, where multiple viewpoints can co-exist. Ibis provides this, and modernizes the terrible “wiki markup” by using our beloved CommonMark Markdown – also used here on Discourse.
We certainly don’t look too authoritative for a Wikipedia article, but we’re definitely authoritative enough to feed the Ibis wiki about our works.