The Internet is awash with medical information. But the most reliable medical information on the web—the contents of peer-reviewed medical journals—is hidden from the public and most of the world’s physicians. Although most medical journals are available online, their publishers limit access to those who choose, and can afford, to pay for access.

Unlike traditional medical journals, which limit access to maximize subscription revenue, the Public Library of Science’s journal PLoS Medicine is a free, open-source, peer-reviewed medical journal. The journal, launched in October 2004, is an international, multidisciplinary medical journal. It publishes studies designed to enhance the understanding of human health and disease and help physicians translate clinical research findings into clinical practice.

Because PLoS believes that medical research is an international public resource, its articles can be downloaded and distributed without restriction as long as the author is given proper credit. Publishing costs are offset by a publication fee charged to authors. PLoS waives the fee for authors with insufficient funds. The ability to pay is not known by the editors, and never affects the decision whether to publish an article.

PLoS was cofounded by Harold Varmus, M.D., former director of the National Institutes of Health (NIH) and corecipient of a Nobel prize for his research in cancer genetics; Patrick Brown, M.D., professor of biochemistry at Stanford University School of Medicine; and Michael Eisen, a computational and evolutionary biologist at Lawrence Berkeley National Laboratory.

PLoS Medicine can be found online at http://www.plosmedicine.org.