ikiwiki-hosting is an interface on top of Ikiwiki to allow easy management of lots of ikiwiki sites. I developed it for Branchable, an Ikiwiki hosting provider. It has a powerful, scriptable command-line interface, and also includes special-purpose ikiwiki plugins for things like a user control panel.
To get a feel for it, here are some examples:
ikisite create foo.ikiwiki.net --admin http://joey.kitenet.net/ ikisite branch foo.ikiwiki.net bar.ikiwiki.net ikisite backup bar.ikiwiki.net --stdout | ssh otherhost 'ikisite restore bar.ikiwiki.net --stdin'