Graphical Kernel System (GKS) has been accepted as an international standard for graphics programming in 1984, Y14.26M (IGES) was adopted as an American Standard in 1981 and the VDA Surface Interface (VDAFS) has been accepted by the German National Standardization Institute (DIN NAM 96.4). Although considerable progress has been achieved, the complexity of the subject and the dynamics of the CAD/CAM-development still calls for more generality and compatibility of the interfaces. This has resulted in an inter­ national discussion on further improvements of the standards. The major goal of this book is to bring together the different views and experiences in industry and university in the area of Product Data Interfaces, thereby contributing to the ongoing work in improving the state of the art.