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.
Denvir is an environment diagnostic library. It should be used by application start-up to check its requirements (for example the right JDK). If a problem occurs, Denvir will provide possible solutions to the end-user.