FreeIPA

[4] FreeIPA aims to provide a centrally-managed Identity, Policy, and Audit (IPA) system.

[5] It uses a combination of Fedora Linux, 389 Directory Server, MIT Kerberos, NTP, DNS, the Dogtag certificate system, SSSD and other free/open-source components.

FreeIPA includes extensible management interfaces (CLI, Web UI, XMLRPC and JSONRPC API) and Python SDK for the integrated CA, and BIND with a custom plugin for the integrated DNS server.

[6] Since version 3.0.0, FreeIPA uses Samba to integrate with Microsoft's Active Directory by way of Cross Forest Trusts.

FreeIPA provides support for Linux, Unix-based, Windows and Mac OS X computers.