Authorea allows researchers to write documents together and attach references, figures, data, and source code. Features of the tool include collaborative editing (multiple people editing a document at the same time), automatic citation formatting, tracking changes, and the ability to make any document public or fully private. When used as an editing tool for scientific papers, Authorea will automatically format a paper in the preferred style and provide files suitable for online submission to peer-reviewed journals and conferences. Over 40 publisher- and journal-specific styles are currently supported.