LDAP (Lightweight Directory Access Protocol) directories are being rapidly deployed on the web. They are currently used to store data like white pages information, user profiles, and network device descriptions. LDAP directories offer scalability advantages over current database technologies, as well as being more flexible. However, as users begin to use them for Directory Enabled Networking tasks such as provisioning network services, allocating resources, reporting, managing end-to-end security, and offering mobile users customized features that follow them, LDAP's limited functionality becomes a significant barrier to progress. For example, LDAP directories do not have active database functionality (i.e., triggers). However, triggers are necessary for monitoring changes to directories and taking appropriate actions, just as they are for databases. Such functionality is crucial to take full advantage of proposals such as the Directory Enabled Network (DEN) initiative. Currently, trigger functionality is non-standardized for LDAP and each vendor's solution is non-portable. We built the Lightweight Trigger Access Process (LTAP) gateway to provide a portable way to add triggers to a LDAP directory. We describe the trigger language, the gateway's implementation, as well as our experiences gained both during implementation and from our users. LTAP is currently being used in several projects. LTAP can be downloaded at http://ltap.bell-labs.com. Copyright © 2000 John Wiley & Sons, Ltd.