Over the years, a number of times, people have asked us about migrating from our own custom Fedora Account System (FAS) to FreeIPA. We would love to, but right now as things stand it's just not a great fit for us. In the past we have had trouble articulating what the issues are, but now Patrick has written up a wiki page with all the items we know of: https://fedoraproject.org/wiki/Infrastructure/fas_freeipa Hopefully we can keep open a dialog with FreeIPA folks and keep the above wiki page synced up so perhaps someday we can migrate when blockers are no longer in our way. :)