Some people use Kerberos instead of LDAP but there's far less people that have actually rolled out a Kerberos implementation that's not related to Active Directory than LDAP. Either way, LDAP and/or Kerberos are just re-inventing wheels that have not a whole lot of value in re-inventing / "innovating" partly because disparate identity and authorization management systems are an immense pain to deal with scaling beyond a small to medium size company and everyone would rather use what's well known first before they think they're smart enough to roll their own. This is pretty typical with developers versus systems management folks though culturally though I'd gather. It just pisses me off when I have to fix something some smartass thought "simpler = better" meant that he should roll his own thing instead of learning how people do it first and THEN rolling his own.