- Buffalo Ontology Site - Large collection of links and papers about Contemporary Ontology, History of Ontology and Ontological Engineering. From the Department of Philosophy, State University of New York.
- CO-ODE - Collaborative Open Ontology Development Environment is a project led by the Medical Informatics Group at the University of Manchester.
- European Centre for Ontological Research (ECOR) - ECOR represents a new approach in applying ontology to a variety of problems in information science and related areas, by coordinating institutions, organisations and companies working in the field.
- Knowledge-Base and Ontology Projects Worldwide - A catalog of links to projects, tools, and events.
- On-To-Knowledge - A project of the European Information Society Technologies, under 5th Framework Program (1999-2002). The project develops knowledge management methods and tools, based on ontology sharing and reuse.
- Ontolog - Ontolog is an open, international, virtual community devoted to advancing the field of ontological engineering and semantic technologies, and advocating their adoption into mainstream applications and international standards.
- Ontologies Come of Age - Paper by Deborah L. McGuinness discussing ontologies and requirements for their effective use on the web. [2002]
- Ontologies For Education - A topic-map driven portal focused on application of ontologies and similar technologies to educational domains.
- Ontology Engineering Background - Overview of methodologies, papers and people.
- Ontology Engineering: a survey and a return on experience - Research report by INRIA, presenting the state of the art of engineering techniques and a project description. (downloadable PDF)
- Ontoweb - The community site for Ontoweb, a European Union founded project about Ontology-based information exchange for knowledge management and electronic commerce.
- OWL Web Ontology Language Reference - Detailed description of the OWL W3C specification.
- Principles of ontology - Mailing list archive. Some basic definitions by John Sowa.
- WonderWeb : Ontology Infrastructure for the Semantic Web - A project aiming at large-scale deployment of ontologies as the foundation for the Semantic Web.
- You're It - A weblog about social tagging.
Media publications
- Adaptive Path - Metadata for the Masses - Discussion of the promise and problems of classification systems created by nonprofessionals. (Published 2004.10.19)
- Ontology is Overrated: Categories, Links, and Tags - Clay Shirky explores online categorization, contrasting ontologies with folksonomies. (Published 2005.05.26)