"SimpleSAMLphp is an award-winning application written in native PHP that deals with authentication. The project is led by UNINETT, has a large user base, a helpful user community and a large set of external contributors.
SimpleSAMLphp is having a main focus on providing support for:
SAML 2.0 as a Service Provider.
SAML 2.0 as a Identity Provider.
But also supports some other identity protocols, such as Shibboleth 1.3, A-Select, CAS, OpenID, WS-Federation and OAuth."