Keycloak
self-hosted, federated identity/authentication service

Keycloak is an open-source identity and access management system that provides centralized authentication and authorization for applications and services. It allows organizations to secure their resources by managing user identities, enforcing access policies, and integrating with various authentication mechanisms such as LDAP, OAuth, and SAML. With Keycloak, developers can easily add authentication and authorization to their applications without the need to implement these features from scratch. It offers a user-friendly administrative console for managing users, roles, and permissions, making it simple to configure and maintain security settings. Whether you're building a web application, mobile app, or microservices architecture, Keycloak provides a robust solution for managing identity and access control.