After almost a year of sometimes contentious debate, the National Institutes of Health has officially opened PubMed Central, a free online archive of full-text, peer-reviewed research papers in the life sciences. While the majority of the major scientific publishers have declined to participate, a number of respected journals will be featured at the site. The first of these are Molecular Biology of the Cell and Proceedings of the National Academy of Sciences of the United States of America. At the time of writing, only the November 1, 1999 issue of Molecular Biology of the Cell was available. Users can view abstracts or the full text of over 30 articles in HTML or .pdf format. The full texts of issues for both journals from 1999 and 1998 are in preparation. Forthcoming journals include Biochemical Journal, Canadian Medical Association Journal, Frontiers in Bioscience, and five journals from BioMed Central. Background and participation information are available at the site. While current offerings at the site are modest, PubMed Central promises to become a major resource for scholars and professionals in the life sciences.