Laue-grams are the easiest X-ray diffraction patterns that can be obtained and are very useful for orienting single crystals and finding out the symmetry of a projection. Despite the simplicity of the experimental equipment, the orientation work is a costly and time consuming process. It would be a great advantage to be able to simulate any kind of Laue-gram and to identify an unknown crystal orientation, including anisotropic ones.This book presents the complete numerical algorithms for simulation of X-ray back-reflection Laue-grams by evaluating the main factors that affect the intensities of the Laue-gram spots. To demonstrate the potential of the computational procedures developed, an example of every crystal system is shown. A PC diskette is included with this book, to be used for simulation and indexing of any back-reflection Laue pattern.