Smart cities advocate future environments where sensor pervasiveness, data delivery and exchange, and information mash-up enable better support of every aspect of (social) life in human settlements. As this vision matures, evolves and is shaped against several application scenarios, and adoption perspectives, a common need for scalable, pervasive, flexible and replicable infrastructures emerges. Such a need is currently fostering new design efforts to grant performance, reuse and interoperability while avoiding knowledge silos typical of early efforts on similar topis, e.g. automation in buildings and homes.