The document discusses ecovillages as models of sustainable living. It defines ecovillages as intentional communities that holistically integrate environmental, economic, social, and cultural sustainability. The document outlines how ecovillages implement sustainability in practice through their social, cultural, ecological, economic, and spiritual dimensions. Some challenges facing ecovillages are lack of land and financing, trends toward globalization and individualism, and maintaining community interests. Overall, the document presents ecovillages as grassroots initiatives that value community living and self-reliance as living models of sustainability.