Found on JavaWorld: An AI tool for the real world-Knowledge modeling with Protégé, an open-source tool for developing ontologies.
While artificial intelligence (AI) is often regarded as an exotic academic playground, its tools and techniques have matured to contribute to real-world software technology as well. This article introduces Protégé, arguably the most successful open source knowledge-modeling platform. Using Protégé, developers and domain experts can build conceptual models and knowledge bases and access them via an easy-to-use Java API. The resulting models can implement decision-support systems, capture software requirements, populate databases, generate Java classes and UML diagrams, share and reuse domain models, and access the Semantic Web.
And the actual project page at Stanford.