This tutorial provides an overview of VR application development using Open Source software tools. We focus on the VR Juggler suite of tools (see http://www.vrjuggler.org) and various Open Source projects that can work with it. We will demonstrate how Open Source software ensures extensibility and eases integration between software tools. We will also show how leveraging existing and emerging Open Source projects can lower development times and costs while simultaneously increasing portability and stability. In particular, we will discuss several kinds of Open Source VR software: • Development frameworks for immersive VR applications (VR Juggler) • Scene graphs for managing application data. (OpenSG or OpenSceneGraph). • Clustering software for powering low-cost VR systems (NetJuggler). • Collaboration software for writing interactive, networked applications (primarily discussing software currently under development by the VR Juggler team). • Various other tools needed to write compelling applications, such as audio libraries, scripting capabilities, and navigation systems, and how they can be used by VR Jugglerbased applications.

Today, scientists and engineers are exploring advanced applications and uses of immersive systems that can be cost-effectively applied in their fields. However, one of the impediments to the widespread use of these technologies is the extensive technical expertise required of application developers. A software environment that provides abstractions from specific details of hardware configurations and low-level software tools is needed to provide a common base for the prototyping, development, testing and debugging of applications. This paper describes VR Juggler, a virtual platform for the creation and execution of immersive applications, that provides a virtual reality system-independent operating environment. We focus on the approach taken to specify, design and implement VR Juggler and the benefits derived from our approach.

With the widespread popularity of the Internet and advances in distributed computing and in virtual reality, more flexibility is needed in the development and use of collaborative virtual environments. In this paper, we present Octopus, a cross-platform, object-oriented API for constructing shared virtual worlds. The list of goals for Octopus, a description of its design and a detailed discussion of its implementation are provided. The design description gives explanations of the three components of Octopus: the core that handles networking and data sharing, the interface for implementing user representations in the virtual space (avatars), and the actual implementations of the avatars.

Virtual reality (VR) installations are often unique; every one is a complex blend of hardware devices, displays and computing resources. The configuration of VR software is therefore a difficult and time-consuming process. VR Juggler, our toolkit for VR application development, addresses these problems with a number of innovations. VR Juggler provides a unique system for organizing the configuration information for a system and minimizing the proliferation of configuration files that many systems suffer. It provides a graphical tool, called VjControl, for editing configurations, which can protect users from many common mistakes. VR Juggler also has advanced capabilities for monitoring and altering the configuration of a running immersive application.