This document provides an overview of single sign-on technologies including Single Sign-On (SSO), Security Assertion Markup Language (SAML), Simple and Protected GSSAPI Negotiation Mechanism (SPNEGO), and OAuth. It defines each technology, provides examples of how they work, and discusses their requirements, limitations, and use cases. The presenter emphasizes choosing solutions based on specific business needs and priorities, as technologies range from relatively easy to implement like single password or SPNEGO, to more complex such as SAML or OAuth.