Cosmopolitan Habitat promotes a research agenda for urban resilience, understanding cities as global avant-garde dealing with the planetary challenges of climate change, migration, and social fragmentation. Within the framework of the “Green Deal”, Europe promotes ideas and innovation for manifest change and long-term strategies to achieve resilience and sustainability. Concurrently, we are confronted by the effects of the Covid-19 pandemic on our cities, and the ways we might re-imagine and construct our urban futures. How might cities become laboratories in which open communities invent, explore, and test strategies to enhance livability, inclusiveness, and sustainable economies? In a wide range of experimental ideas and research essays spanning European and international cities, Cosmopolitan Habitat presents conceptual models, urban strategies, and spatial practices of the Open City, across urbanism, architecture, other artistic and scientifc disciplines, culture, economy, and politics.