- [FreeIPA](https://www.freeipa.org/) - Integrated security information management solution combining Linux (Fedora), 389 Directory Server, Kerberos, NTP, DNS, and Dogtag Certificate System (web interface and command-line administration tools). ([Source Code](https://pagure.io/freeipa)) `GPL-3.0``Python/C/JavaScript`
- [FreeRADIUS](https://freeradius.org/) - Multi-protocol policy server (radiusd) that implements RADIUS, DHCP, BFD, and ARP and associated client/PAM library/Apache module. ([Source Code](https://github.com/FreeRADIUS/freeradius-server)) `GPL-2.0``C`
- [lldap](https://github.com/nitnelave/lldap) - Light (simplified) LDAP implementation with a simple, intuitive web interface and GraphQL support. `GPL-3.0``Rust`
- [LTB Self-Service Password](https://www.ltb-project.org/documentation/self-service-password.html) - Web interface to change and reset LDAP passwords. ([Source Code](https://github.com/ltb-project/self-service-password)) `GPL-3.0``PHP`
- [OpenLDAP](https://www.openldap.org/) - Open-source implementation of the Lightweight Directory Access Protocol (server, libraries and clients). ([Source Code](https://git.openldap.org/openldap/openldap)) `OLDAP-2.8``C`