Best Open‑Source SSO Platforms Supporting SAML and OIDC Standards

Full‑featured identity and access management solution with built‑in SAML 2.0 and OIDC support, social login, user federation, and fine‑grained authorization.

Enterprise‑grade IAM platform offering SAML, OIDC, UMA, and LDAP integration; includes a powerful admin UI and extensive customization options.

Mature SAML 2.0 IdP widely used in academia; can be paired with external OIDC providers or the Shibboleth SP for hybrid deployments.

Comprehensive IAM suite supporting SAML 2.0, OIDC, OAuth2, SCIM, and XACML; includes adaptive authentication and API security features.

Modern, container‑native identity provider built on Python/Django; offers SAML 2.0, OIDC, LDAP, and SCIM with a sleek UI.

Perl‑based web SSO solution supporting SAML 2.0, OIDC, CAS, and OpenID; includes a powerful policy engine and multi‑tenant capabilities.

Lightweight PHP library for SAML 2.0 and OIDC; often used as an IdP or SP in small‑to‑medium deployments.

Java‑based Central Authentication Service supporting SAML, OIDC, OAuth2, and WS‑Federation; highly extensible with a large plugin ecosystem.

Open-source access management platform (now community‑maintained) offering SAML 2.0, OIDC, OAuth2, and fine‑grained policy enforcement.

Lightweight OIDC identity provider that can act as a SAML bridge via external connectors; often used with Kubernetes and GitOps workflows.

OAuth2 & OIDC server that can be combined with Ory Kratos for full SSO; supports SAML 2.0 via the Ory Hydra SAML bridge plugin.

Identity & user management system; when paired with Ory Hydra it provides SAML‑compatible SSO flows and OIDC out‑of‑the‑box.

Self‑hosted authentication portal for web services; supports OIDC and can proxy SAML through external IdPs, ideal for reverse‑proxy environments.

Free edition of FusionAuth offering SAML 2.0, OIDC, LDAP, and SCIM; includes a modern UI and extensive developer APIs.

Open‑source identity platform built on Go; provides native OIDC, SAML 2.0, and multi‑tenant SaaS‑ready features.

Open‑source .NET Core implementation of OpenID Connect and OAuth2; can be extended with SAML2P via community packages.

Open‑source identity governance and administration (IGA) platform; includes SAML and OIDC connectors for provisioning and SSO.

Identity management engine that can act as a SAML IdP and OIDC provider; often paired with OpenAM for full IAM stacks.

Modular SAML/OIDC gateway that sits in front of existing IdPs; enables protocol translation and attribute enrichment.

Lightweight reverse‑proxy that adds OIDC authentication to any service; can forward SAML assertions when combined with Keycloak.

Integrated security information management solution; includes Kerberos, LDAP, and can expose SAML/OIDC via the FreeIPA‑SSO plugin.

Open‑source authentication server built on Go; supports OIDC, SAML, LDAP, and provides role‑based access control via Casbin.

Free community edition of the Gluu Server offering full SAML 2.0 and OIDC capabilities with a web UI and REST APIs.

Node.js library that can act as a minimal SAML IdP/SP and also expose OIDC endpoints; suitable for lightweight custom SSO solutions.

Community‑driven fork of ForgeRock OpenAM; continues to provide SAML 2.0, OIDC, and OAuth2 support.

Kubernetes operator that deploys and manages Keycloak clusters; inherits full SAML and OIDC capabilities for cloud‑native environments.

Kong API gateway plugin enabling OIDC authentication; can be paired with external SAML IdPs to provide hybrid SSO.

Node.js library for building a standards‑compliant OIDC provider; can be extended with SAML support via plugins.

Open‑source bridge that translates SAML assertions to OIDC tokens and vice‑versa, enabling legacy SAML apps to use modern OIDC IdPs.

Component of the Gluu ecosystem that allows OIDC‑only deployments to expose SAML endpoints for legacy applications.

Legacy open‑source SSO platform that still runs in many environments; supports SAML 2.0 and OIDC via community extensions.

Next‑generation Keycloak codebase focused on cloud‑native deployment; retains full SAML and OIDC support while offering improved performance.