Cityleft brings together the City and Copyleft concepts. Founded in 2005 to disseminate the activities of a PhD in urban and regional planning at University of Catania, today Cityleft showcases projects and research investigations conceived and delivered mainly by Agatino Rizzo in collaboration with a network of researchers, students, public institutions, and professional practices.

Cityleft literally means open source, P2P urbanism, a concept developed in 2009 by a group of urban thinkers which included Agatino Rizzo. In 2015, Agatino Rizzo together with M Galanakis departed from P2P thinking to focus on the performative aspects of activism and the relationship between this latter and the complexity science of cities and socio-spatial approach. In this endeavor they developed a new methodological framework called Transdisciplinary Urbanism.