This web site contains a collection of directories that are being maintained by John F. Sowa. For each entry, click on the icon at left to go to the index page for the corresponding directory. Clicking on the owls will take you to a biographical sketch of the webmaster.

Conceptual graphs around the world Conceptual Graphs are a system of knowledge representation based on the semantic networks of AI and the logic of Charles Sanders Peirce. This directory contains the draft proposed ANSI standard for CGs, some examples and tutorials about CGs, a bibliography of books about CGs, and links to web sites with CG tools and resources.
Knowledge Representation book

The book Knowledge Representation by John F. Sowa has recently been published. This directory contains some information about the book, including on-line copies of the preface and the table of contents. The on-line index contains over 600 links to web sites that contain background readings about the people and topics mentioned in the book.

Fire lives the death of earth, and air the death of fire; water lives the death of air, earth that of water.  Heraclitus Ontology is the study of existence. An ontology is a system of categories for classifying and talking about the things that are assumed to exist. This directory contains a summary of the ontology developed and used in the KR book by John Sowa.
A typical twentieth-century computer. Computer systems of the twenty-first century will be based on the principles of computer science that were established during the nineteenth and twentieth centuries. This directory contains memoirs, observations, and predictions about computer history. At the moment, it contains only one web page, which discusses the law of standards.
The panda is a miscellaneous animal -- a vegetarian carnivore. Any system of classification inevitably has miscellaneous stuff that doesn't quite fit in the other categories. This directory contains some of that stuff, including a tutorial on the mathematical background that is used, mentioned, or referenced in the other web pages.
No spam, please. As Heraclitus observed, all things are in flux, and you cannot step twice into the same web site. The pages in these directories may undergo minor changes at any time. Please send any updates, corrections, or reports of broken links to sowa (AT)