The 1977 book A Pattern Language was a landmark in the design world, introducing a methodology that has become influential across many fields. Among them are software and ¿design patterns,¿ and important spinoff technologies like wiki (the basis of Wikipedia) and Agile Methodology. Yet curiously, the field where pattern methodology began ¿ the built environment ¿ has lagged conspicuously. As one remedy, a number of long-time collaborators with the original book¿s lead author have followed the explicit guidance of the book, and developed a new collection of 80 patterns offering tools and strategies for a new era of urban challenges. This new collection emerged in part from a five-year collaboration with UN-Habitat to address new urban challenges, including rapid urbanization, slum upgrading, sustainable urbanism, and new technologies. Together with the launch of an online companion pattern ¿repository¿ (available at [...]) this volume aims to expand the capacity of pattern languages in support of a hopeful new era of open-source, human-centered, life-enriching technology.