EarthTrends -- a comprehensive online database, maintained by the World Resources Institute, that focuses on the environmental, social, and economic trends that shape our world.
Ecosustainable Hub -- this site provide a one-stop connection to resources and tools to a signficant variety of resources related to ecology, environment, and sustainability and the application of sustainable technologies to waste treatment, recycling, housing, architectural design, project development, ethical finance, sustainable living, recreation, and renewable energy.
Sustainable Development Online -- provides access to significant web sites built by organizations supporting the move towards sustainable development with descriptions of and links to hundreds of web sites. Site is part of EnviroWindows, the European Environment Agency platform for knowledge sharing and development.
Sustainable Cities Research Institute -- a research and consultancy institute based within the School of the Built Environment, Northumbria University, Newcastle upon Tyne, England. Includes a resource page to additional links.
United Nations Human Settlements Programme -- UN-HABITAT, is the United Nations agency for human settlements. It is mandated by the UN General Assembly to promote socially and environmentally sustainable towns and cities with the goal of providing adequate shelter for all. Web site contains statistical data and numerous research reports.