Guix

389ds is an enterprise-class LDAP server. It is hardened by real-world use, is full-featured, and supports multi-master replication.

Other features include:

1. Online, zero downtime, LDAP-based update of schema, configuration, and management including Access Control Information (ACIs);

2. Asynchronous Multi-Master Replication, to provide fault tolerance and high write performance;

3. Extensive documentation;

4. Secure authentication and transport (TLS, and SASL);

5. LDAPv3 compliant server.