Security Assertion Markup Language (SAML)
SAML is a standard defined by Oasis that describes an authentication and authorization protocol. This protocol defines the necessary communication flow between systems the ultimate result of which is a trust-assertion message on behalf of the user which is consumed by the target system to determine that they were A.) authenticated and B.) authorized to specific entitlments on the target system.
Details on SAML see: http://www.oasis-open.org/home/index.php
