bioRxiv is a preprint server for the life sciences. Now in beta version, it hopes to do for the life sciences what the ArXiv preprint server has done for physics - serve as a freely accessible preprint publishing venue. Hosted by Cold Spring Harbor Laboratory, it accepts papers in the following subject areas: biochemistry, bioengineering, bioinformatics, cancer biology, cell biology, developmental biology, ecology, evolutionary biology, genetics, genomics, immunology, microbiology, molecular biology, molecular medicine, neurobiology, paleontology, pathology, physiology, plant biology, scientific communication, synthetic biology, systems biology and zoology.