By Jonathan Corbet
PostBooks® has been around as a commercial project since 2000 or so; it made the shift to a free software project in 2007. It is, however, a classic example of a corporate-controlled project, with the corporation in this case being a company called xTuple. The license is the "badgeware" Common Public Attribution License (CPAL), which requires the acknowledgment of the "original contributor" on splash screens and similar places. The CPAL is recognized as an open source license by the Open Source Initiative, but its attribution requirements are not popular with all users. The CPAL has not taken the world by storm; it has shown up in a few business-oriented projects like PostBooks®, though.