Penrose is a java-based virtual directory server. Virtual directory enables federating (aggregating) identity data from multiple heterogeneous sources like directory, databases, flat files, and web services - real-time - and makes it available to identity consumers via LDAP.
Shibboleth is standards-based, open source middleware software which provides Web Single SignOn (SSO) across or within organizational boundaries. It allows sites to make informed authorization decisions for individual access of protected online resources in a privacy-preserving manner.