Metaphysics Research Lab
Originating from the Center for the Study of Language and Information, Ventura Hall, Stanford University, Stanford, CA 94305-4115. A technical, but interesting site, which describes itself as follows: "Whereas physics is the attempt to discover the laws that govern fundamental concrete objects, metaphysics is the attempt to discover the laws that systematize the fundamental abstract objects presupposed by physical science, such as natural numbers, real numbers, functions, sets and properties, physically possible objects and events, to name just a few. The goal of metaphysics, therefore, is to develop a formal ontology, i.e., a formally precise systematization of these abstract objects. Such a theory will be compatible with the world view of natural science if the abstract objects postulated by the theory are conceived as (possible) property-patterns of the natural world. In our research lab, we have developed such a theory: the axiomatic theory of abstract objects and relations. In many ways, this theory is l ike a machine for detecting abstract objects (hence the name `research lab'), for among the recursively enumerable theorems, there are statements which assert the existence of the abstract objects mentioned above. Moreover, the properties of these abstracts can be formally derived as consequences of the axioms. The theory systematizes ideas of philosophers such as Plato, Leibniz, Frege, Meinong, and Mally. Our results are collated in the document Principia Metaphysica, which is authored by Edward N. Zalta (Ph.D./Philosophy), a Senior Research Scholar at CSLI. An online version of Principia Metaphysica can be found by following the link to The Theory of Abstract Objects (see below). In published work, the theory has been applied to problems in the philosophy of language, intensional logic, the philosophy of mathematics, and the history of philosophy."

Noesis
Check this for new site information, and adding a search link to my page.