RIDE is a roadmap project for interoperability of eHealth systems leading to recommendations for actions and to preparatory actions at the European level. This roadmap will prepare the ground for future actions as envisioned in the action plan of the eHealth Communication COM 356 by coordinating various efforts on eHealth interoperability in member states and the associated states. Since it is not realistic to expect to have a single universally accepted clinical data model that will be adhered to all over the Europe and that the clinical practice, terminology systems and EHR systems are all a long way from such a complete harmonization; the RIDE project will address the interoperability of eHealth systems with special emphasis on semantic interoperability. In order to create RIDE Roadmap, first the European best practices in providing semantic interoperability for eHealth domain will be assessed and the quantified requirements to create a valid roadmap will be identified. Based on these requirements, the goals, and the economical, legal, financial and technological challenges of the industry for the 21st century for achieving interoperability in eHealth solutions will be elaborated. RIDE will also focus on the limitations of the policies and strategies currently used in deploying interoperable eHealth solutions. A research portal for sharing resources addressing semantic interoperability in eHealth domain will be created and maintained; the key actors and stakeholders will be coordinated around RIDE special interest groups to create a wide consensus at the European level. Through eight RIDE workshops a shared vision for building a Europe-wide semantically interoperable eHealth infrastructure will be created. After assessing the gaps between the 'as-is' situation and the 'to-be' eHealth vision, the emerging trends and opportunities to achieve the vision statement, the required advances in the state of the art research, technology and standards will be identified.