You can use many applications to view and edit Massive Wikis.
One helpful tool, Massive Wiki Builder, converts a Massive Wiki into a static HTML website, for easy viewing on the web. It is a "static site generator" for Massive Wikis.
You can see MWB on the Massive Wiki Conceptual Diagram, in the center.
Massive Wiki Builder is used to recreate the main Massive Wiki website from its Markdown source files every time someone pushes changes to GitHub.
For more information, see the Massive Wiki Builder repository on GitHub.