Exploring and addressing the challenges of urban social ecosystems has gained focus, with various initiatives aiming at combining competitiveness and sustainable urban development. Several European cities have already deployed sophisticated ICT infrastructures as a means to offer added-value services to their citizens, in order to cope with societal challenges while at the same time enabling new business lines.Nevertheless, in order to achieve efficient service provision, several dimensions – including technology, socio-economics, governance and legal – must be considered. While important research outcomes have been made available to tackle one or more of them, a structured and comprehensive, user-engaging and quick way for development and deployment of Smart City services is not fully supported yet.RADICAL will ease the fast creation of interoperable and socially-aware services, by leveraging Internet of Things and Social Networking technologies, emerging from the results of four R&D EU-funded projects: SmartSantander, BonFIRE, SocIoS, and +Spaces.A number of services will be integrated, deployed and piloted on top of the RADICAL platform. This platform will also facilitate tools for the smart governance and flexible replication of services across cities and regions, thus shortening the time to market and allowing SMEs, citizens and local authorities to get fully involved in the smart city businessThe RADICAL services belong to the areas of Cycling Safety, Green Products Management, Data Journalism, Participatory Urbanism, Augmented Reality and Eco-consciousness . These services will be supported by five technical SMEs and accordingly replicated across six five smart cities and one smart region. Over 2400 citizens will be actively involved in the co-creation, validation and evaluation of the RADICAL approach, on the basis of the Living Lab methodology, which will engage users of the entire stakeholder chain.