MediaWiki and Mercurial (Hg) Integration

"People have used mercurial and other DVCSs as the backend for wikis (see ikiwiki for an example), but generally they're not a great fit because you create a new changeset across all pages/files for each edit of any page/file.

However, it sounds like you're just looking to use mercurial as a backup for your mediawiki instance, which is sort of a mismatch. The wiki already saves previous revisions, and exporting to a DVCS would do the same thing in a different way. You're better off just backing your wiki daily using the export/archive features it provides and pushing it to cheap storage."