For several years the authors of this book have been involved in the design and the national and international review of the forthcoming graphical standard. When the end of this process could be foreseen and the International Standard "Graphical Kernel System" (GKS) was cast into its. final form, the urgent need arose for detailed information to the graphics community about this stan dard and for the education of graphics programmers. One major goal of GKS, besides the portability of graphical application programs and the device inde pendence, is "programmer portability" by establishing a common base for train ing of graphics programmers. Having accompanied the path of GKS from the very early stages of defining the basic concepts and designing its first versions up to the final draft of the International Standard, we feIt it worthwhile to start the venture of a text book on computer graphics programming based on GKS. This book is aimed, at one hand, at graphics users, experts and managers who want to get an overview of the new standard and a better understanding of its concepts. On the other hand, it addresses the graphics programmers who want to use GKS for realizing their graphical applications. It can serve as the base for teaching and studying functions, concepts and methods of GKS. Addi tionally, it will be a valuable source of information for implementors of GKS.