The paper presents the main results of the IST FP6 INFRAWEBS project. The project has developed an easy and effective way of constructing and using semantic descriptions for existing and new Web services. INFRAWEBS has adopted the WSMO (Web Service Modeling Ontology) and WSML (Web Service Modeling Language) specifications and has imposed no additional requirements to them. Therefore, the advanced software components developed during the project are of interest to the whole WSMO community. INFRAWEBS offers a SOA framework – INFRAWEBS Integrated Framework (IIF), based on the ESB integration paradigm, which can be easily used by different groups of users (application providers, designers of SWS, etc.). The IIF enables integration of components of different technologies. Furthermore, it can be considered as one of the first frameworks for semantic service engineering that covers the whole SWS life-cycle and allows for creation of complex, semantically-enabled applications.