Section 2 Acknowledgments
¶This book grew out of a class in non-Euclidean geometry taught for more than two decades at Oregon State University. Initial experimentation with a variety of software for working with models of non-Euclidean geometry eventually led to a choice to use GeoGebra. However, there was no single location where one could explore all the geometries used in the course, including finite geometries, the Poincaré Disk, the Klein Disk, and Minkowski space. The goal of this book is to remedy that deficiency.