Miraheze

Miraheze is a free, non-profit wiki hosting service that uses MediaWiki as its hosting engine, it provides any extension of your choice, including VisualEditor and Flow. Miraheze is not advertising supported, and does not put advertising on wikis it hosts.

Extensions
Miraheze can download any extension of your wish and enable it on your wiki. Many of these can be found at Wikimedia's git repository (the official MediaWiki git). To see extensions that are currently downloaded on Miraheze see their github.

There are also Extensions by Miraheze, available as free open source software.

Custom domains
If requested, Miraheze provides support for custom domains, but under domains some conditions.