Ontologies have become core components of many large applications yet the training material has not kept pace with the growing interest. This paper addresses the issues of why one would build an ontology and presents a methodology for creating ontologies based on declarative knowledge representation systems. It leverages the two authors experiences building and maintaining ontologies in a number of ontology environments including Protege-2000, Ontolingua, and Chimaera. It presents the methodology by example utilizing a tutorial wines knowledge base example. While it is aimed at users of frame-based systems, it can be useful for building ontologies in any object-centered system.

Protégé is an ontology editor and a knowledge-base editor.

Protégé is also an open-source, Java tool that provides an extensible architecture for the creation of customized knowledge-based applications.

Protégé's OWL Plug-in now provides support for editing Semantic Web ontologies.

• RACER is a Semantic Web inference engine for
  • developing ontologies
  • query answering over RDF documents and wrt. specified RDFS/DAML and OWL ontologies
  • registering permanent queries (e.g., for building a document management system) with notification of new results if available (publish-subscribe facility)
• RACER is a Description Logic reasoning system with support for
  • TBoxes with generalized concept inclusions
  • ABoxes
  • Concrete domains (e.g., linear (in-)equalities over the reals)
• RACER is a prover for modal logic Km with graded modalities and axioms

Supports semi-automatic creation of ontologies by applying text mining algorithms. Currently includes term extraction algorithm, concept association extraction algorithm and ontology pruning algorithm.

Life science researchers traditionally chain together database searches and analytical tools, using complex scripts to overcome incompatibilities, or by manually cutting and pasting between web interfaces. These "in silico” experiments are usually undertaken without support for the scientific process of managing, sharing and reusing the results, their provenance, and the methods used to generate them. The myGrid project has developed a comprehensive loosely-coupled suite of middleware components specifically to support data intensive in silico experiments in biology. Workflows and query specifications link together third party and local resources using web service protocols. ...

To support in silico experiments in biology, myGrid has researched and developed open source high-level service-based middleware, drawing on innovative technologies from the semantic web community. A registry, with mechanisms to support descriptions drawn from an ontology defined in the W3C standards RDF and OWL, enables service providers and bioinformaticians to publish, discover and match-make services, and bioinformaticians to publish and reuse workflows. The Knowledge Annotation and Verification of Experiments component (KAVE) captures and stores provenance records of methods and purpose in RDF, and again semantically annotated by terms from an ontology.

UCD (Unified Content Descriptors) is a controlled vocabulary for describing astronomical data quantities.

A model for expressing knowledge organization systems in a machine-understandable way, within the framework of the Semantic Web.

OWL is a Web Ontology language. Where earlier languages have been used to develop tools and ontologies for specific user communities (particularly in the sciences and in company-specific e-commerce applications), they were not defined to be compatible with the architecture of the World Wide Web in general, and the Semantic Web in particular.

OWL uses both URIs for naming and the description framework for the Web provided by RDF to add the following capabilities to ontologies:

• Ability to be distributed across many systems
• Scalability to Web needs
• Compatibility with Web standards for accessibility and internationalization
• Openess and extensiblility

OWL builds on RDF and RDF Schema and adds more vocabulary for describing properties and classes: among others, relations between classes (e.g. disjointness), cardinality (e.g. "exactly one"), equality, richer typing of properties, characteristics of properties (e.g. symmetry), and enumerated classes.

The W3C Semantic Web Activity Statement explains W3C's plans for OWL deployment, including the Web Ontology Working Group, Best Practices and Deployment Working Group and the Semantic Web Interest Group.

The Semantic Web provides a common framework that allows data to be shared and reused across application, enterprise, and community boundaries. It is a collaborative effort led by W3C with participation from a large number of researchers and industrial partners. It is based on the Resource Description Framework (RDF), which integrates a variety of applications using XML for syntax and URIs for naming.

"The Semantic Web is an extension of the current web in which information is given well-defined meaning, better enabling computers and people to work in cooperation." -- Tim Berners-Lee, James Hendler, Ora Lassila, The Semantic Web, Scientific American, May 2001

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