How can we live together in ways that are healthy and sustainable for people and the planet? This book tells the story of people attempting to live intentionally and sustainably by practicing ideals of nonviolence, participatory democracy, and voluntary simplicity. Between 2011 and 2015, I conducted ethnographic research in over twenty intentional communities, which can be broadly defined as residential communities organized around shared values, around the US. These communities understand themselves as demonstration communities, developing and testing, but not imposing, new patterns of living, eating, and communicating. Communities in this book include ecovillages, cohousing communities, and Catholic worker houses and farms, located in urban, rural, and suburban regions. The initial chapters of the book explore why people come to these communities, who comes, and what they do when they get there, including growing food, creating governance systems, and building community. Each faced similar sets of challenges that are familiar to us: most people are ambivalent in our attitudes towards authority, regulation, and community. The final chapters suggest ways to apply what these communities have learned in the context of our own lives and regions. Food co-ops, pocket neighborhoods, and cohousing, for example, offer some benefits of intentional communities such as control over food but require fewer drastic lifestyle changes.