mediawiki-skins
There are 3 repositories under mediawiki-skins topic.
immewnity/mediawiki-fluent
Fluent skin for MediaWiki
iSCInc/skins
Collects all skins for a iSC Inc. wiki. Find it under https://skins.inc.isc and https://git.wikimedia.org/tree/mediawiki%2Fskins.