GeoSmartCity contributes to the Smart City implementation by establishing a cross-platform, re-usable and open hub able to publish open geographic information and to provide specialized services based on open standards. GeoSmartCity leverages the use of open (geo)data as recommended by the EU Open Data Strategy and starts from PSI and INSPIRE Directives data infrastructures, with an emphasis on Municipalities as service and data providers to professionals and citizens.The GeoSmartCity cross-platform toolkit and operational methodology allow further integration of third-party data (open or restricted) as well as crowd-sourced data. Exploitation of heterogeneous (open) GI data will be possible thanks to the connection of different consolidated standards (linked data, INSPIRE, Sensor data, GNSS), allowing open cross-sector interoperability between different data providers and domains and the consequent creation of a wide range of user-driven applications.The potentiality of the toolkit will be demonstrated through the development of 11 operative and re-usable pilot cases in the frame of two scenarios: Green-Energy scenario, to facilitate diffusion and management of renewable energy within cities, and Underground scenario, to support integrated management of underground utility infrastructures. These pilot cases will demonstrate the possibility to apply the GeoSmartCity Hub and its specialized services in different areas and municipalities, guaranteeing the exploitability and the long term viability of the proposed solution, in new cities and sectors.GeoSmartCity Hub will be community software and the business model will be based on development of extensions, applications and services as well as geo-statistical analysis. The non-proprietary platform will also foster increased emphasis on standardization and interoperability of detailed, local data that do not conform to generic standards for European data sets.