Lasso (Liberty Alliance Single Sign On) is an
implementation of the Liberty Alliance
specifications. These specifications define
protocols for federated identities, single
sign-on, etc. Lasso supports ID-FF 1.2, SAML 2.0,
and parts of ID-WSF. It provides both a C library
and bindings for several languages (Python, Java,
Perl, PHP 4, and PHP 5).