Who shapes our cities? In an age of increasing urban pluralism, globalization and immigration, decreasing public budgets, and an ongoing crisis of authority among designers and planners, the urban environment is shaped by a number of non-traditional stakeholders. The book surveys the kaleidoscope of views on the agency of urbanism, providing an overview of the various scholarly debates and territories that pertain to bottom-up efforts such as everyday urbanism, DIY urbanism, guerilla urbanism, tactical urbanism, and lean urbanism. Uniquely, this books seeks connections between the various movements by curating a range of views on the past, present, and future of bottom-up urbanism. The contributors also connect the recent trend of bottom-up efforts in the West with urban informality in the Global South, drawing parallels and finding contrast between social and institutional structures across the globe. The book appeals to urbanists in the widest sense of the word: those who shape, study, and improve our urban spaces.