  This paper describes the achievements of the H2020 project INDIGO-DataCloud.
The project has provided e-infrastructures with tools, applications and cloud
framework enhancements to manage the demanding requirements of scientific
communities, either locally or through enhanced interfaces. The middleware
developed allows to federate hybrid resources, to easily write, port and run
scientific applications to the cloud. In particular, we have extended existing
PaaS (Platform as a Service) solutions, allowing public and private
e-infrastructures, including those provided by EGI, EUDAT, and Helix Nebula, to
integrate their existing services and make them available through AAI services
compliant with GEANT interfederation policies, thus guaranteeing transparency
and trust in the provisioning of such services. Our middleware facilitates the
execution of applications using containers on Cloud and Grid based
infrastructures, as well as on HPC clusters. Our developments are freely
downloadable as open source components, and are already being integrated into
many scientific applications.
