- [Authelia](https://www.authelia.com/) - The Single Sign-On Multi-Factor portal for web apps. ([Source Code](https://github.com/authelia/authelia)) `Apache-2.0``Go`
- [Authentik](https://goauthentik.io/) - Flexible identity provider with support for different protocols. (OAuth 2.0, SAML, LDAP and Radius). ([Source Code](https://github.com/goauthentik/authentik)) `MIT``Python`
- [KeyCloak](https://www.keycloak.org) - Open Source Identity and Access Management. ([Source Code](https://github.com/keycloak/keycloak)) `Apache-2.0``Java`
- [Kratos](https://www.ory.sh/kratos/) - Next-gen identity server with Ory-hardened authentication, MFA, FIDO2, profile management, identity schemas, social sign in, registration, account recovery, and IoT auth. Golang, headless, API-only - without templating or theming headaches. ([Source Code](https://github.com/ory/kratos)) `Apache-2.0``Golang`