Ikiwiki supports using several revision control systems for storing page histories.
Ikiwiki started out supporting only Subversion, but the interface ikiwiki uses to a revision control system is sufficiently simple and generic that it can be adapted to work with many systems by writing a plugin. Subversion is still a recommended choice; git is another well-tested option.
These are all the supported revision control systems:
Git
Posted Fri Feb 12 12:53:17 2010
mercurial
Posted Fri Feb 12 12:53:17 2010
darcs
Posted Fri Feb 12 12:53:17 2010
cvs
Posted Fri Feb 12 12:53:17 2010
monotone
Posted Fri Feb 12 12:53:17 2010
tla
Posted Fri Feb 5 05:16:25 2010
svn
Posted Fri Feb 5 05:16:25 2010
bzr
Posted Fri Feb 5 05:16:25 2010
There is a page with details about how the different systems work with ikiwiki, for the curious.