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.
GNU Prolog API for distributed multithreading programming built on top of the PM2 environment. The thread management is made with a user-level multithreading library and communication is made on top of Madeleine, the communication subsystem of PM2.