Federated Wiki
A Federated Wiki is a new type of wiki created by Wiki inventor, Ward Cunningham and others, they work similarly to Federated Social Networks.
A wiki can be create by anyone; you just install the software and run it on a server. But changes to pages can be pushed or pulled cross-wiki. If you don't want to run your own, you can choose a Wiki Community/Provider that in alignment with your preferences.
From Ward Cunningham's GitHub:
We imagine two components:
1. a server component managing page storage and collaboration between peer servers, and, 2. a client component presenting and modifying the server state in server specific ways.
This project should be judged by the degree that it can:
Demonstrate that wiki would have been better had it been effectively federated from the beginning. Explore federation policies necessary to sustain an open creative community.