OpenLDAP - OpenLDAP Software is an open source implementation of the Lightweight Directory Access Protocol.
pfSense - pfSense is a free and open source firewall and router that also features unified threat management, load balancing, multi WAN, and more
389 Directory Server - Enterprise-class open source Linux LDAP server.
Zentyal - Linux directory, domain, mail, gateway and infrastructure server for SMBs.
FreeIPA - FreeIPA is an integrated security information management solution combining Linux (Fedora), 389...
NethServer - NethServer is an operating system for Linux enthusiasts, designed for small offices and medium...