"The Green.org Sustainability Challenge is a simple challenge to
communities (as well as organizations and individuals with IT
expertise within those communities) to leverage Drupal to create
location-specific Drupal instances. These instances form the basis
for organically growing social networks based on existing local
relationships and through local community-based activities. Such
online communities can be sustained by volunteer labor, as well as
generating revenue through advertising and e-commerce. Local social
networks support the community and build strength to face and
overcome local challenges."