One application domain for Service Oriented Architectures (W3C Work. Group 2004) is ontology and metadata processing in the semantic web. Ontology-based approaches (Amann et al. 2002) pursue the interoperability among different sources of information by envisioning the development of software systems cooperation based on the sharing of semantics about data. Ontology Web Services are SOA implementations of ontology middlewares and systems functionalities published on the web and accessible by external applications via SOAP. In this work we report our experiences in developing and testing the OntologyWeb Services of the ReMuNa (Remuna Project 2006) framework. The paper discusses the main advantages and drawbacks of using Web Services technology to implement services acting on ontology as input/output.