The Apache Directory Server (ApacheDS) is an embeddable LDAPv3 directory
server with other protocol plugins such as kerberos. It is designed to
be completely pluggable in every aspect including backends and frontend
handlers making making it an ideal experimentation platform for LDAP
protocol testing, and for use in building other tools like like meta
directories, and virtual directories. ApacheDS aims to introduces
stored procedures, triggers, views, and queues to the world of LDAP.