Knowledge Representation

KR, Inc. - Charitable organization concerned with fostering research and communication on knowledge representation and reasoning. Features conferences, educational materials and mailing lists.
http://www.kr.org

Tockit Project - Aims to create a framework for conceptual knowledge processing in terms of social structures and a common code base. Features software description and contact details.
http://tockit.sourceforge.net/

John Sowa on Knowledge Representation - Provides background material and tutorials on ontology and related topics in logic, conceptual graphs, and natural language semantics.
http://www.jfsowa.com/

Action Theory Contraction and Minimal Change - Article by Ivan José Varzinczak, postdoc researcher in artifical intelligence at universities in France and South Africa, building on Propositional Dynamic Logic. [PDF]
http://ivanjv-en.890m.com/wp-content/uploads/2008/06/varzinczak-kr2008.pdf

Conceptual Graphs Home Page - Features introductory material and bibliography, standard notation, events, projects, tools and researchers.
http://www.cs.uah.edu/~delugach/CG/

Knowledge Interchange Format (KIF) - A DARPA project. KIF is a language designed for use in the interchange of knowledge among disparate computer systems.
http://logic.stanford.edu/kif/kif.html

Knowledge Representation Resources - A list of knowledge representation resources, part of the AI Education Repository at the University of Southwestern Louisiana.
http://www.cs.cofc.edu/~manaris/ai-education-repository/

WebKB - A set of tools using Conceptual Graphs formalism for building and documentation of knowledge bases, indexing or connecting elements of WWW-accessible documents.
http://www.webkb.org/