: Building the Semantic Web requires the use of powerful tools to create, manage and extend domain ontologies represented with Semantic Web languages. Though many tools have been already developed, unfortunately there is a lack of practice using them in real-world applications. The suitability of these tools and the underlying technologies, especially w.r.t. performance and scalability parameters, is still an open issue. This paper focuses on problems and experiences gained in the project "A Semantic Web for Pathology", a research project using domain ontologies and ontology-driven natural language processing to support a content-based storage and retrieval for text and image-based medical information.