Objectives: While research communities from different disciplines have different ambitions and approaches – particularly with respect to data organization and content – they do share many basic service requirements. This commonality makes it possible for EUDAT (European Data Infrastructure) to establish common data services, designed to support multiple research communities, as part of a Collaborative Data Infrastructure (CDI). By providing generic services to existing scientific communities, EUDAT enables research communities to focus a greater part of their effort and investment on services that are discipline-specific. EUDAT also provides individual researchers, smaller communities, and projects lacking tailored data management solutions with access to sophisticated shared services, thus removing the need for large-scale capital investment in infrastructure development. Lastly, by providing opportunities for disciplines from across the spectrum to share data and cross-fertilize ideas, EUDAT encourages progress towards the vision of open and participatory data-intensive science. EUDAT is a research data infrastructure initiative funded by the European Commission’s FP7 programme (2011-2014) to build a sustainable cross-disciplinary and cross-national infrastructure that provides a set of shared services for accessing and preserving research data. The project is coordinated by CSC and brings together a consortium of 25 partners, including national data and high performance computing (HPC) centers, technology providers, research communities, and research councils from 13 countries.