Kanidm

FreeIPA is an integrated security information management solution for Linux/Unix environments, combining LDAP, Kerberos, DNS, and certificate services for centralized identity and authentication.

An open-source LDAP (Lightweight Directory Access Protocol) server implementation for Linux, developed by Red Hat.

OpenLDAP is an open-source implementation of the Lightweight Directory Access Protocol (LDAP) for directory services and authentication.

Authentik is an open-source identity provider that focuses on flexibility and integration with modern infrastructure. It provides authentication, authorization, and user management for applications and APIs.

Authelia is an open-source authentication and authorization server that provides single sign-on and two-factor authentication for web applications. It can be deployed as a reverse proxy to protect internal services.

Keycloak is an open-source identity and access management solution that provides single sign-on, user federation, and social login capabilities for web applications and services.

Zitadel is an open-source identity and access management platform that provides authentication, authorization, and user management with a focus on developer experience.