A decade ago, a significant trend toward openness emerged in international development. “Open development” can describe initiatives as disparate as open government, open health data, open science, open education, and open innovation. The theory was that open systems related to data, science, and innovation would enable more inclusive processes of human development. This volume, drawing on ten years of empirical work and research, analyzes how open development has played out in practice Focusing on development practices in the Global South, the contributors explore the crucial questions of who is allowed to participate when an initiative is “open” and who benefits—or not—from them, finding that processes characterized as open can sometimes be exclusionary in their implementation. Examining a wide range of cases, they consider the governance of open development ecosystems and the implementation of a variety of applications, including open educational resources, collaborative science, and the uses of crowdsourcing. Denisse Albornoz, Chris Armstrong, Savita Bailur, Roxana Barrantes, Carla Bonina, Michael Cañares, Leslie Chan, Laura Czerniewicz, Jeremy de Beer, Stefano De Sabbata, Shirin Elahi, Alison Gillwald, Mark Graham, Rebecca Hillyer, Cheryl Hodgkinson-Williams, Dick Kawooya, Erika Kramer-Mbula, Paulo Matos, Caroline Ncube, Chidi Oguamanam, Angela Okune, Alejandro Posada, Nagla Rizk, Isaac Rutenberg, Tobias Schonwetter, Fabrizio Scrollini, Ruhiya Kristine Seward, Raed Sharif, Matthew Smith, William Randall Spence, Henry Trotter, François van Schalkwyk, Sonal Zavaeri