The success of PubMed Central, the Open Archives Initiative, and SPARC will help to improve access within the subscription-based model. Other initiatives challenge the subscription-based model outright and offer an alternative, article processing charge. Most prominent among these are BioMed Central (http://biomedcentral.com) and the Public Library of Science. BioMed Central is an independent commercial publisher, committed to providing free and immediate online access to the full text of peer-reviewed biomedical research. Authors retain copyright. BioMed Central has more than 90 peer-reviewed journals spanning the fields of biology and medicine, and provides free technical support and hosting for groups of researchers wanting to run online, open access, peer-reviewed journals under their own editorial control. The company receives no support from governments or from scientific societies. Instead of charging users, BioMed Central covers the costs of peer review and publication by charging authors for processing manuscripts.14 The charge, US$500 per published article in 2003, could be paid directly by authors, usually from their research funds, or via their institutes through BioMed Central's membership scheme. In 2003, BioMed Central has 291 institutional members from 29 countries. The charge is waived for authors from developing countries and others who are unable to pay.