McCullough Knowledge Explorer (MKE) is an intelligent knowledge assistant. It helps the user to record, change and search knowledge, and provides extensive error checking to ensure the internal consistency of the knowledge. Interaction with MKE uses the MKR language. MKR is a RI ("Real Intelligence") knowledge representation language; it is very user-friendly, combining the best features of English, UNIX-shell, Unicon, CycL.

Knowledge is an identification of the facts of reality. Propositional knowledge is knowledge expressed using words and sentences. The principal internal knowledge structures are entity-characteristic-proposition hierarchies with space-time-dependent events. The principal external knowledge structures are RDF/OWL files, GDBM databases and MKR text files (containing transliterated English, hierarchy outlines, relational databases).

The MKR language is more powerful and more user-friendly than the OWL language. MKR extensions include context, questions, commands/methods, n-ary relations, iterations, conditionals. MKE/MKR provides no direct support for the "possible world" semantics of RDF model theory -- it uses "real world" semantics of English. The MKR language has the same power as the CycL language, but is much more user-friendly.

MKE provides a user-friendly MKR interface to the Stanford TAP knowledge base, the OpenCyc knowledge base, the Google search engine, the Amazon.com search engine.