"Directory services play a vital part in today's networks by helping
administrators manage network users and resources. Until recently, the
only choice for deploying a secure and easy-to-use open source directory
server was OpenLDAP. While it gets the job done, it lacks the polish of
commercial alternatives. Now Fedora Directory Server (FDS), Red Hat's
open source LDAP server, makes setting up an enterprise directory server
on Linux simple."