are "squatted" by publishers claiming ownership on these works,
and selling them at a high price. The work of researchers is
often publicly funded, especially in North America. It would
therefore seem appropriate that the scientific community and
the general public can freely enjoy the results of such
research. In science and medicine for example, more than 1,000
new articles reviewed by peers are published daily.

The Public Library of Science (PLoS) was founded in October
2000 by biomedical scientists Harold Varmus, Patrick Brown and
Michael Eisen, from Stanford University, Palo Alto, and
University of California, Berkeley. Headquartered in San
Francisco, PLoS is a non-profit organization whose mission is
to make the world's scientific and medical literature a public
resource in free online archives. Instead of information
disseminated in millions of reports and thousands of online
journals, a single point would give access to the full content
of these articles, with a search engine and hyperlinks between
articles.

PLoS posted an open letter requesting the articles presently
published by journals to be distributed freely in online
archives, and asking researchers to promote the publishers
willing to support this project. From October 2000 to September
2002, the open letter was signed by 30,000 scientists from 180
countries. The publishers' answer was much less enthusiastic,
although a number of publishers agreed for their articles to be
distributed freely immediately after publication, or six months
after publication in their journals. But even the publishers
who initially agreed to support the project made so many
objections that it was finally abandoned.

Another objective of PLoS was to become a publisher while
creating a new model of online publishing based on free
dissemination of knowledge. In early 2003, PLoS created a non-
profit scientific and medical publishing venture to provide
scientists and physicians with free high-quality, high-profile
journals in which to publish their work. The journals were PLoS
Biology (launched in 2003), PLoS Medicine (2004), PLoS Genetics
(2005), PLoS Computational Biology (2005), PLoS Pathogens
(2005), PLoS Clinical Trials (2006) and PLoS Neglected Tropical
Diseases (2007), the first scientific journal on this topic.

All PLoS articles are freely available online, on the websites
of PLoS and in the public archive PubMed Central, run by the
National Library of Medicine.