389 Directory Server (formerly Fedora Directory Server) is a full-featured LDAPv3 compliant server. In addition to the standard LDAPv3 operations, it supports multi-master replication, fully online configuration and administration, chaining, virtual attributes, access control directives in the data, Virtual List View, server-side sorting, SASL, TLS/SSL, and many other features. The transactional Berkeley DB 4.2 is used as its data store and a full plug-in API allows developers to extend the the functionality of the server in many ways, and many of the core features of the server are already implemented using this API. The server is very mature, having started out as Netscape Directory Server.
Kolab is a groupware system that provides a comprehensive and flexible solution for workgroups. Email, contacts, and group calendars can be managed via the Web, Windows/Outlook, and Linux/KDE. It supports offline synchronization and full seamless support of mixed client environments because the Kolab-XML storage format is fully open and avoids MAPI/TNEF.
PasswordNotify was written to solve a long-standing need of ActiveDirectory and OpenLDAP administrators. It simply queries your LDAP server once a day and notifies a user when their password is about to expire. It is highly customizable, and runs as either a Unix cron job or a Windows service.
Zentyal (formerly eBox Platform) is a small business server that offers small and medium businesses an affordable and easy-to-use enterprise-level computer network. It can act as a Gateway, Infrastructure Manager, Unified Threat Manager, Office Server, Unified Communication Server, or a combination of these.
Samba LDAP Tools++ is a branch of the smbldap-tool scripts. It has Kerberos (Heimdal) support for passwords, LDAP hashes, and domain machines; support for DynDNS updates on Samba using BIND; and additional structures for system users that allow a single user to play different roles as RADIUS, LDAP, Kerberos, Samba, and Jabber users. It has many additions and functions that allow full support on new technologies.
Crowd is a Web-based single sign-on (SSO) tool that simplifies application provisioning and identity management. It has connectors for popular open source projects like Apache (via Perl) and Subversion. Pre-built connectors for other popular commercial products like Jive Forums, JIRA, and Confluence are also available.
JeguePanel is a panel to provide easy management of GNU/Linux servers. It makes services configuration (email and samba) much more easy and efficient, and handles user and permissions management. It's integrated with monitoring tools and a lot of control programs like anti-virus, anti-spam, reports, etc. It has English, Portuguese, and Spanish translations. It can use OpenLDAP, PostgreSQL, or MySQL as a backend, and has full integration with Active Directory. It will show different interfaces to users based on permission levels.