The Web Service Modeling Ontology (WSMO) is a conceptual model for creating semantic descriptions that can be used to resolve interoperability issues between web services. These descriptions can be used to dynamically discover, compose, mediate, select and invoke web services. Tool support for WSMO is in its infancy and there is a need for tools that support the creation of WSMO descriptions and provide value added features to the users of such tools by exposing the complexities that exist within these descriptions. This paper introduces WSMOViz, an integrated ontology engineering and ontology visualization tool for WSMO, supporting the user through the ontology engineering process.