Last modified: 2013-07-23 23:58:45 UTC
The source code of the Nimbus skin is currently located at the historical skins/ folder under the mediawiki/extensions/ repository, which predates the mediawiki/skins/ repository. Since Nimbus is a skin, it obviously should be under the skins repository. :)
Jack talked to me on IRC and this isn't urgent. Moving repos is still a pain, so I'll do it when I'm back.
This is now done.