Wikimedia hosts a lot more Wiki’s than their headliner Wikipedia.
I’m familiar with Wikimedia through, Wikipedia but also Mediawiki, which organisations, groups and individuals can use to create their own Wikis on their hosted platform for free!
However, there are other Wiki’s out there:
Wikisource – Free library
Wikimedia Commons – illustrations, photos, drawings, video and music
Wikiversity – learning resources
wikivoyage – travel guide
And many more!
IT Owl 