Similar in scope to the Encyclopedia of Life, the Encyclopedia of Earth is an impressive online “reference about the Earth, its natural environments, and their interaction with society. The Encyclopedia is a free, fully searchable collection of articles written by scholars, professionals, educators, and experts who collaborate and review each other’s work.”
Topics range from “Agriculture and food” to “Net energy analysis” and “Toxicology”; subtopics are available under each topic. Articles are displayed Wikipedia-style, with terms linked to their own entries in the encyclopedia. A handful of e-books are also available, such as Environment and Globalization: Five Propositions and “classics” (in e-book format) like Darwin’s On the Origin of Species.
In poring over this resource I found only one U.S. government agency that provided content for the work, with most of it being provided by “experts” in their field, non-profit organizations like the Munasinghe Institute for Sustainable Development, Conservation International, The Canada Institute of the Woodrow Wilson International Center for Scholars, and a couple of academic institutions.
Another interesting angle is that all the text is under the Creative Commons license, and RSS is enabled for most of the articles. This encyclopedia is definitely worth checking out.