This chapter presents detailed design of the Virtual Machine-based Proxy (VMP). We first give an overview of the VMP architecture, and then present efficient communication mechanisms based on compression and adaptation techniques. On the proxy side, we present resource management techniques to optimize the performance of the VMs and cloud techniques to address scalability issues. Security and privacy issues are addressed, and a technique based on trusted computing module is presented. Finally, we discuss deployment issues and issues on supporting interactive applications.