PostBooks is a proprietary accounting and enterprise resource planning business system geared toward small to medium-sized businesses. It used to be released under an open source CPAL license on GitHub, but was made non-free in June 2019. Postbooks was based on the commercially licensed xTuple ERP system created by xTuple, a private software company based in Norfolk, Virginia (VA), United States. Name The name PostBooks is derived from three aspects of the project. The first "Post" alludes to the common concept of posting journals in accounting. Second, the name refers to the project's technological roots as it runs exclusively on the PostgreSQL database. Finally, the name suggests PostBooks as a logical step of progression for businesses that have outgrown the popular QuickBooks small business accounting product by Intuit. History PostBooks is the foundation of the xTuple ERP software developed and marketed by the company of the same name beginning in the year 2000. All of the xTuple ERP Editions are targeted toward small to midsize companies. PostBooks is offered on a commercial base in the Distribution Edition, the Manufacturing Edition, and the Enterprise Edition. The first stable release of PostBooks was version 2.2.0 announced in September 2007 when its code was first made publicly available on SourceForge. Since then source code management has been moved to GitHub. On June 20, 2019 it was announced the distribution of the free PostBooks Editions has been discontinued. Functionality PostBooks is divided into 7 functional modules: Accounting, Sales, CRM, Manufacture, Purchase, Inventory and Products. It supports multi-currency and multi-language capability and is therefore suited for international deployment. All modules are integrated into a single common code base in the client, and reside in a single database schema on the server. The difference between PostBooks and commercial editions is completely managed in the database schema where the Commercial database includes additional tables and functions to support larger enterprises. The PostBooks project includes two application interface options: a locally installed Graphical User Interface (GUI) client and a REST based web services API for integration with third-party applications, all of which feed into the same PostgreSQL back end database. The GUI client is using a client–server methodology written in C++ using the Qt framework. Both the Qt client and PostgreSQL database server may be run on Windows, Macintosh, or Linux operating systems. The GUI client also uses the OpenRPT report writer and renderer as its embedded reporting