Interoperability, which brings major benefits for enterprise and science, is key for the pervasive adoption of grids & clouds. Interoperability between existing grids and clouds is of primary importance for the European Union today. Many of the policy issues required to achieve interoperability with DCIs across the world are already being explored through the Infrastructure Policy Group (IPG) that meets regularly and which has representation from major production e-Infrastructures globally. SIENA, in 2 years, shows how Europe, which has already invested heavily on building e-infrastructures, addresses issues regarding the adoption of grid, cloud and distributed computing infrastructure standards. SIENA starts at a strategic point in time when the development of standards and interoperability is a key priority to be addressed, especially in RTD activities, and where it is evident that the ICT standardisation landscape is dramatically making more of an impact than ever in the last decade. While the grid concept developed to support the federation of research computing resources, the cloud concept developed to support the dynamic provisioning of computation, storage and communications with attractive business models. Given the scope of these developments, it is recognized that no one organization can manage the entire landscape of potential activities. The need to augment community building across user groups with community building across standards organizations to drive specification adoption forward in order to achieve these goals is key.In detail:- Drive forward the development and adoption of Interoperability and Standards in relation to the European DCI community & SDOs;- Elaborate the future research infrastructure scenario through roadmapping connecting into relevant SDOs to drive forward production of relevant standards & best practices.- Support, plan & organise a series of outreach events viz: 2 roadmap international events in Europe, 2 Cloudscape workshops.