Prolog+CG is a Java implementation of Prolog with extensions implementing a subset of the Conceptual Graph (CG) theory of John Sowa. CGs are first-class datatypes on a par with terms. Object oriented extensions are also included.
The PeerTrust system uses policies to describe trust and security requirements. Such policies are a component of Peertrust run-time system that can negotiate to establish trust among systems on the Semantic Web