PeerJ is an open access peer-reviewed scientific mega journal covering research in the biological and medical sciences. It is published by a company of the same name that was co-founded by CEO Jason Hoyt (formerly at Mendeley) and publisher Peter Binfield (formerly at PLOS One), with initial financial backing of US$950,000 from O'Reilly Media's O'Reilly AlphaTech Ventures, and later funding from Sage Publishing.PeerJ officially launched in June 2012, started accepting submissions on December 3, 2012, and published its first articles on February 12, 2013. The company is a member of CrossRef, CLOCKSS, ORCID, and the Open Access Scholarly Publishers Association. The company's offices are in Corte Madera (California, USA), and London (Great Britain). Submitted research is judged solely on scientific and methodological soundness (as at PLoS ONE), with a facility for peer reviews to be published alongside each paper. Business model PeerJ uses a business model that differs from traditional publishers – in that no subscription fees are charged to its readers – and initially differed from the major...