This document discusses the development of urban data platforms and smart city initiatives. It outlines the key stakeholders in urban data platforms, including municipalities, companies, startups, app developers, and citizens. It also discusses the current status of urban data platforms, from exploring and planning to operational stages. Additionally, it identifies several facilitators and inhibitors to effective urban data platforms, such as lack of business cases, technical standards, and cultural/social issues. Finally, it discusses the scale-up potential and market opportunities for further developing and expanding urban data platforms across city clusters nationally and internationally.