Ganymede is a GPL'ed Network Directory Management System.
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. Whenever a change is committed to the database, the Ganymede server dumps out a bunch of data files and runs backend scripts to update your network directory services. All changes are logged, and Ganymede can send email to your users and administrators notifying them of account activity.
Ganymede is both multithreaded and multi-user. Many users and admins can be browsing and making changes to the Ganymede database simultaneously. The Ganymede server supports transactions, and transparently handles locking and concurrency issues to guarantee referential data integrity during concurrent editing. Ganymede supports fine-grained delegation, so that you can allow arbitrary subdivision of authority over your network directory services. If you want to have a single NIS domain for your organization but you want certain administrators to be able to edit only certain user accounts, Ganymede makes it easy.
Finally, Ganymede is highly customizable. You can customize the server's schema definitions to handle whatever sort of directory data you want to manage, and data can be imported from any source you like using Ganymede's flexible XML interface. You can create custom Java classes to generate any sort of data files, and your own back-end builder scripts in your favorite scripting language to handle the distribution of directory updates. You can create administration tasks to be run automatically by the Ganymede scheduler, and you can create plug-in classes to oversee almost every aspect of the editing process.
At ARL:UT, we use Ganymede to manage NIS, DNS, a Windows NT domain controller, Samba, Sendmail, tacacs, and LDAP. If you have a lot of network directory services that you'd like to unify without having to rearchitect your network systems around LDAP or Active Directory, Ganymede may be the tool for you.