MAD uses it rather extensively. That's one of the reasons you see a confusing mashup of case in docs relating to AD. DNS: example.co.uk, Kerberos Realm: EXAMP

MAD uses it rather extensively. That's one of the reasons you see a confusing mashup of case in docs relating to AD. DNS: example.co.uk, Kerberos Realm: EXAMPLE.CO.UK To add confusion there is the NETBIOS shortname for a "Domain" (which is really a realm) which in this case could be EXAMPLE or EX or whatever. As a Linux sysadmin/user in an MS world, I have pretty much managed to Kerberize everything I can get my hands on via Samba (winbindd). I also use Evolution with the EWS plugin to get to Exchange and use Kerberos to auth to that. All my sshd's support GSSAPI auth and so does PuTTY for my Windows loving colleagues. Firefox and Chrome(ium) support GSSAPI. Whether I like it or not, MAD is here to stay and so I have to embrace it .... 8) I have fully documented build docs for several Linux distros for our corp needs. I now have feature parity with Windows for our use cases. A bit more testing and tweaking needed to cover edge and corner cases, then I will get a volunteer to try it out, etc etc. One step at a time. Anyway, to answer your question: everywhere that has AD installed or FreeIPA and the like and of course places that use Kerberos itself eg MIT!