ISPMan is a system to design massive ISPs using LDAP as the backend.
ISPMan provides a web front end and a command line interface to create virtual domains and manages users, dns information, email infos and httpd setup data for these vhosts.
This project aims to provide an easy to use interface to Samba, openLDAP, and Printing (via cups, iptables, emerge and apt-get. It currently is command-line based, and has the beginnings of a graphical interface via kommander (see quanta).
LIMeTool (pronounced like the fruit), is intended to be a simple and easy interface for managing accounts on an integrated Sendmail/LDAP/Cyrus IMAP installation. It's written in PHP and is realitively easy to configure and expand.