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. 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. The articles can be freely redistributed and reused under a Creative Commons license, including for translations, as long as the author(s) and source are cited. PLoS also launched PLoS ONE, an online forum where people can publish articles on any subject relating to science or medicine.
Three years after they were created, PLoS Biology and PLoS Medicine had the same reputation for excellence as the leading journals Nature, Science and The New England Journal of Medicine. PLoS received financial support from several foundations while developing a viable economic model from fees paid by published authors, advertising, sponsorship, and paid activities organized for PLoS members. PLoS also hopes to encourage other publishers to adopt the open access model, or to convert their existing journals to an open access model.