This book describes the software for creating networked, 3D multi-user virtual environments that allow users to create and remotely share visualizations of program behavior. The authors cover the major features of collaborative virtual environments and how to program them in a very high level language, and show how visualization can enable important advances in our ability to understand and reduce the costs of maintaining software. The book also examines the application of popular game-like software technologies.   • Discusses the acquisition of program behavior data to be visualized • Demonstrates the integration of multiple 2D and 3D dynamic views within a 3Dscene • Presents the network messaging capabilities to share those visualizations.