Link to this headingSSO

Single Sign on
Headless cloud-native authentication and identity management written in Go

Link to this headingPocket ID

Pocket ID - Lightweight SSO solution

Link to this headingAuthelia

Authelia Repo - Open-source authentication and authorization server providing 2FA and single sign-on portal for web applications.
Authelia HAProxy Integration Guide - Official documentation for integrating Authelia with HAProxy reverse proxy.

Link to this headingKeycloak

Keycloak - Enterprise-grade identity and access management solution supporting OAuth 2.0, OpenID Connect, and SAML protocols.

Link to this headingAuthentik

Link to this headingKratos

https://github.com/ory/kratos