In Domino R6, there is tight integration between the Domino Address Book and Active Directory. This is explained in detail in the Domino 6 administrator's guide. In general, the two directories can be synchronized easily, with tools built into R6. Account creation is also synchronized, so the administrator is not creating the same account twice. It does not appear that Active Directory can replace the Domino Address Book, however.
This was first published in May 2003