The Global Ecovillage Network is an online repository and community for all things Ecovillage. Its most important function is to propogate ecovillage values and provide a Consensus model for linking ecovillages across the world into a holistic, but diverse collection of efforts in a planetary context, while providing tools and resources for a myriad of local contexts, ranging from revolutionary efforts to establish ecocities to humble efforts to promote things like organic gardening in neighborhoods.
The Global Ecovillage Network was formed in the early 1990's following a gathering of intentional communities and related organizations with a sustainability focus at Findhorn. Robert and Diane Gilman did a study of "ecovillages" which led to the formation of GEN with the help of funding from Gaia Trust.
GEN has a huge database listing ecovillages worldwide.