polis

Streamline your web application's authentication with Polis, an SSO service supporting SAML and OpenID Connect protocols. Beyond enterprise-grade Single Sign-On, it also supports Directory Sync via the SCIM 2.0 protocol for automatic user and group provisioning/de-provisioning. Maintained by ory on GitHub, where it has earned 2,263 stars from the community.

It's actively developed around enterprise-software, saml, saml2, and is a solid reference for anyone building with these tools.