xTuple is an Enterprise software company, author of xTuple ERP. There are three versions of xTuple ERP: Manufacturing Edition, Standard Edition, and PostBooks Edition.
xTuple Technology Edit
The two tier design of the xTuple solutions intentionally places the burden of transaction processing on the server - specifically the database server. All the business logic resides in the procedural language of the open source database PostgreSQL, allowing for a variety of client interfaces and scalability unbound by client-side limitations. The primary interface today is a full, rich graphical user interface (GUI) client - this allows for a client that looks and feels exactly the same on Windows, Linux/Unix, and Mac.
PostBooks/OpenMFG GUI Client Edit
The GUI client is written in Qt, from Trolltech, headquartered in Norway. Qt is a C++ toolkit for application development. It lets application developers target all major operating systems (Windows, Linux/Unix, Mac) with a single application source code. Qt provides a platform-independent API to all central platform functionality: GUI, database access, networking, file handling, etc. The Qt library encapsulates the different APIs of different operating systems, providing the application programmer with a single, common API for all operating systems. The native C APIs are encapsulated in a set of well-designed, fully object-oriented C++ classes.
PostBooks/OpenMFG Server/Business Logic Edit
The xTuple applications make heavy use of Postgres' embedded procedural language, called PL/PGSQL. Whenever any kind of transaction is taking place in the system - a financial account being credited or debited, a piece of inventory being moved, or an order being taken - that is happening in a Postgres stored procedure, trigger, or function. This approach makes it relatively easy for other client software besides the PostBooks graphical client to access business functionality. xTuple partners and customers have developed various alternative interfaces to access the Postgres backend database, including Web portals, wireless devices, and desktop office productivity software.