Half of the world population today lives in cities. That proportion reaches two-thirds in some countries, and urban dwellers around the globe face many of the same problems: poverty, homelessness, precarious housing, noise, inadequate sanitation and sewerage services, air and water pollution and deficient schools. Solutions cannot be achieved at the local or global levels without the active participation of city governments and residents. How do city dwellers confront their common problems? IPS tracks their pursuit of healthy and sustainable development of the urban environment, especially improving the lives of people who live in impoverished neighbourhoods.