Soil is home to vast numbers of organisms, and even small sections of earth teem with a diverse array of life. This Topic in Depth takes a closer look at the world beneath our feet through the lens of soil biologists and ecologists. The first website (1) provides information about the activities of a Natural Environment Research Council-supported research program "on the biological diversity of soil biota and the functional roles played by soil organisms in key ecological processes." The second site (2) contains information about several research projects of the Ecology of Soil Organisms Theme Group at Wageningen University and Research Centre. The Theme Group studies "soil organisms at the population, community, and ecosystem level, to ultimately increase understanding of the role of soil organisms." The third site (3) contains a list of publications spanning the past fifteen years from members of the Soil Ecology Group at the University of Jyv'skyl". The site also provides basic information about group members, and concise descriptions of current research projects. From the USDA Natural Resources Conservation Service, the fourth website (4) contains an online version of the _Soil Biology Primer_, "an introduction to the living component of soil and how it contributes to agricultural productivity, and air and water quality. The Primer includes units describing the soil food web and its relationship to soil health, and units about bacteria, fungi, protozoa, nematodes, arthropods, and earthworms." The online version of the Primer contains the entire text of the original published version, but is missing some useful soil organism images. The fifth site (5) links to sixteen movies relating to different aspects of soil biology such as nematodes, mites, springtails, and protozoa. The movies were all produced by Dr. Thomas E. Loynachan, a Professor of Agronomy and Microbiology at Iowa State University. Finally, Soils Are Alive (6) was developed by Professor Lyn Abbot of the University of Western Australia and Jen Slater, a qualified secondary school science teacher. This website contains informative, concise sections addressing Soil Biology, Biological Processes, Living Components, and Ecosystem Management.