This chapter serves as an accessible introduction to some key concepts that are used to describe contemporary urban commons and commoning and as an overview of situated experiments in public-commons cooperation and governance, that have adapted these through a variety of protocols, institutional designs, and social, technical, and ecological innovations. Drawing on the experiences of the cities of Ghent, Barcelona, and others, as well as recent developments in peer-to-peer production and value accounting, it makes a case for urban contributive democracy, and finally, cosmolocal production, a planetary mutualization strategy.