Interiki's primary design is meant to achieve master-slave authentication relationships between multiple Tiki sites. It's designed to allow several satellite sites authenticate against one central source for user data.
Additionally Intertiki can be used to transfer user profiles from the primary user source and their corresponding groups. Both of these choices are configurable and allow for a wide range of authentication and user data share paradigms.
Intertiki can be extended for several other purposes with additional custom development utilizing XMLRPC's ability to query just about any asset of user data in a tiki.
Please see: doc:InterTiki