Security Assertion Markup Language (SAML) is an XML-based framework defined by OASIS for communicating assertions about identity. SAML allows for the implementation of single sign-on (SSO) for federated identity management across distributed applications and platforms.
References:
https://www.oasis-open.org/committees/tc_home.php?wg_abbrev=security
https://www.pingidentity.com/resource-center/SAML-Tutorials-and-Resources.cfm
http://login.salesforce.com/help/doc/en/sso_saml_assertion_examples.htm