Ganymede is a GPL’ed project that develops a super-directory management system. From it, data is published down to any variety of network directories. From the homepage:
<blockquote><p>Ganymede is designed to manage network directory services such as NIS, DNS, Netinfo, and LDAP. The Ganymede server contains an object database of your network directory data, which users and admins can browse and edit using a polished GUI client.</p></blockquote>