Available methodologies for developing Sematic Web applications do not fully exploit the whole potential deriving from interaction with ontological data sources. Here we introduce an extension of the WebML modeling framework to fulfill most of the design requirements emerging for the new area of Semantic Web. We generalize the development process to support Semantic Web applications and we introduce a set of new primitives for ontology importing and querying. Categories and Subject Descriptors H.5.4 [Information Interfaces and Presentation]: Hypertext/Hypermedia-- Architectures, Navigation; D.2.2 [Software Engineering]: Design tools and techniques--Computeraided software engineering (CASE) General Terms Design, Languages, Theory Keywords Semantic Web, Design Method, Ontology, Web Engineering, Conceptual Model