Two types of metadirectory products--directory sync and join-based--offer solutions to the directory management dilemma. Directory synchronization products, such as NetVision's Synchronicity, aim primarily to copy objects and attributes between two or more directories using a single directory service as the master. We found Synchronicity easy to implement and an effective solution for small-to-medium-sized networks.

However, larger installations that need to synchronize multiple data sources and implement complex attribute flows and management roles are best served with a join-based metadirectory such as Zoomit's VIA Server. VIA implements a separate directory to logically manage large object spaces and maintain complex relationships (such as joining objects without common names or identifiers), providing a powerful, if complex, toolkit for implementing customized directory synchronization strategies.