Keywords: living technology, urbanism, adaptation, robustness, learning, self- organization. 1 Urban Advantages and Disadvantages More than half of the world population lives in cities [33]. With 180,000 people moving to cities every day [82], urban population is expected to grow, reaching 70% of the global population by 2050 [28, 113]. There are several advantages of urban settlements, such as less energetic requirements per capita, higher incomes, innovation, and productivity [69, 24, 23]. In spite of—or perhaps because of—being highly attractive for people, modern cities also face several problems, such as mobility, crime, disease, pollution, and other social problems. There have been several proposals concerning every urban problem, with different de- grees of success. There are cities where the major problem might be mobility (Mexico City, Beijing [70]), safety (Ciudad Ju´ arez, Baghdad), unemployment (Detroit, Madrid), segrega- tion (Chicago, Pretoria), traffic accidents (El Cairo, Dar-es-Salaam), or lack of infrastructure (Lagos, Kabul). Since there are different causes for different problems, there will be no single solution for all urban problems: several solutions have to be explored in parallel. Urban planning has been guiding the development of cities for decades, at least in de- veloped countries. Planning is certainly useful: it is better to deal with situations before they become problematic. However, urban planning has been rigid so far: how can fu- ture requirements be predicted as cities grow and embrace new technologies and customs? Just like a century ago cities were not planned to use cars as major means of transporta- tion, cities cannot be planned now for their requirements of the next fifty years. Moreover, it is only recently that researchers have been able to develop descriptive models of urban growth [3, 4, 137, 118, 93]. The limitations of urban prediction are due to the complexity of cities [64, 78, 60]. Com- 2