The Shibboleth V2 IdP and SP software have reached End of Life and are no longer supported. This documentation is available for historical purposes only. See the IDP v4 and SP v3 wiki spaces for current documentation on the supported versions.
The easiest way to determine the IdP version is through the use of the IdP version command line tool. Just execute $IDP_HOME/bin/version.sh, if you're on a Unix system or $IDP_HOME/bin/version.bat if you're on a Windows system.