MediaWiki has DataDump^1, and ArchiveTeam has a bot that can use it this extension as an API to mass-archive many wikis at once. Very useful since it gives an archive of article revisions and images in a machine-readable format that can be used to recreate the entire wiki, minus user accounts.

^1: https://www.mediawiki.org/wiki/Extension:DataDump

Screenshot: https://i.imgur.com/4LUn9Nv.png