Cities must address the increased number of service coordination and planning challenges because of urban sprawl. Citizens need better healthcare, cities need to decrease costly administrative overheads, not to mention the inefficient transportation systems, increasing communication and connectivity demands and finally inefficiency of the current energy systems. As cities face these substantial and interrelated challenges, it becomes clear that the ‘business as usual’ model has become obsolete. The Smart City concept responds more immediately and effectively, allows to local government to anticipate and fix the problems and thus minimize the impact of future disruptions. To implement a smart city is a complex task, involving different aspects and several actors. In recent years, many cities all over the world have been started to design and implement their own smart strategy, involving a large set of different players. As a smart city is especially based on the use of innovative technologies in the urban areas, three main actors are involved in its implementation: local government, research institutions and technology vendors. Local government is steering the planning of the "Intelligent City" and general aspects for the benefit of the inhabitants; research institutions offer their competences in studying and experimenting innovative technologies and solutions; vendors produce and sell technological platforms and infrastructures for the smart city realization. A linking role is played by consulting companies - systems integrators, offering coordination of all players and interoperability in these complex projects.