From Authentication Tools for Joomla! (JAuthTools)

Sync

This bot is designed to provide synchronization between existing Joomla! users and LDAP. The bot is designed to be the last to operate and directly modifies session and user data to achieve its integration.

Additionally, a backend synchronization system is being developed to provide a separate source of integration.

Adv Sync

With JAuthTools 1.0.9 for Joomla! 1.0 the Advanced Synchronisation mambot was released to enable support for synchronising to a seperate database table. This system requires the name of an external table, a foreign key in that table linked to the users table and optionally a primary key which may also be the same as the user ID foreign key. Finally a sync map is used to match fields from the table to LDAP.

Note: For Joomla! 1.5 this is supported via the User Sources system.