This book comprises articles by some of the well-known international experts presented at the 2008 Dagstuhl seminar on Virtual Reality (VR). The articles include position statements, subjects discussed during the seminar, and relevant research covering the following topics: constrained 3D user interfaces, social gaming and learning applications, future VR software platforms, the next generation of augmented reality systems the importance of experiential fidelity, and fundamental methods to compelling applications.  .