Personal mobile devices (MDs) have evolved tremendously during recent years. The use of MDs is becoming pervasive; the hardware con-figurations are enhanced to be comparable to low-end desktop systems; and there are drastic improvements in the wireless communication infrastructures. These trends make novel applications and business models by deploying virtual environments (VEs) for MDs promising and desirable. However, to make the key elements of a VE, i.e. visualization and interaction, work as smoothly on MDs as on desktop systems, three research challenges need to be addressed: 1) which visual factors of a VE make the user's realism perception similar to that in the physical world? 2) How to effectively allow a user to collect his/her own biometric data to build personalized profiles? 3) How to efficiently make use of the processing resources in the infrastructure for the computing-intensive tasks of an individual user, such as intelligent human computer interaction? Read this book about a framework that strives for the solutions.