In development agencies, paradigms of linear causality condition much thinking and practice. They encourage command-and-control hierarchies, centralize decision making, and dampen creativity and innovation. Globalization demands that organizations see our turbulent world as a collection of evolving ecosystems. To survive and flourish they must then be adaptable and fleet-footed. Notions of complexity offer a wealth of insights and guidance to 21st century organizations that strive to do so.