The Encyclopedia of Earth
The Encyclopedia of Earth is a "new electronic resource about the Earth, its natural environments, and their interaction with society. It is a free, fully searchable collection of articles written by scholars, professionals, educators, and experts who collaborate and review each other's work. The articles are written in non-technical language and will be useful to students, educators, scholars, professionals, as well as to the general public." Althougt the Encyclopedia is a wiki, all content is reviewed and approved by editors prior to being published.