GSD Platform 3 presents a selection of work produced during the 2009-2010 academic year of the Harvard University GSD and the potential of that work to address broader questions and inform global initiatives. Whether exploring the potential of a new technology, redefining a typology, or engaging a community on the other side of the globe, the lines of inquiry beginning at the GSD consistently indicate relevance to larger social, cultural, and spatial questions. To understand the scope of this potential impact, the work was framed with one simple question: "What can design do?". We have identified five actions that describe the ability of Architecture, Landscape Architecture, and Urban Planning and Design at the GSD to reach beyond their immediate contexts and out into the world: Instigate Evolution, Describe Identity, Construct Equality, Negotiate Growth, Imagine New Futures. The range and definition of these actions is tested through the work of a representative collection of studios, lectures, seminars, symposia, colloquia, thesis projects, and student research. The core studios are presented here in sequence. Each of these featured entries expands the limits of design and invites us to reconsider the role of the architect, the landscape architect, the urban planner and designer in defining the world of the future. Preface by GSD's Dean Mohsen Mostafavi and introduction by Emily Waugh, GSD's lecturer in Landscape architecture.