In 1991, an electronic system through which interested parties could access non-peer-reviewed physics papers was launched by Paul Ginsparg at Los Alamos National Laboratory. This evolved into the “preprint” server arXiv, which has played a central role in information sharing in physics, mathematics, and related fields over many years. Recently, other preprint servers have been or are being developed to serve other fields including biological sciences, chemistry, and medicine (see the News story on p. 1344). Given the different cultures associated with these disciplines, and other external factors, policies and practices must evolve as these servers become integrated into their communities.