Security Assertion Markup Language (SAML) is a standard for logging users into applications based on their sessions in another context.
Security Assertion Markup Language (SAML) is an XML-based open standard for exchanging authentication and authorization data between security domains, that is, between an identity provider (a producer of assertions) and a service provider (a consumer of assertions).
SAML is a product of the OASIS Security Services Technical Committee.
Also see SAML2.0