The document summarizes Sun VDI 3.1 architecture for desktop virtualization. It discusses the virtualization layer including hypervisors like VirtualBox and VMware. It describes the session management layer for desktop life cycles and assignments. It also outlines methods for desktop access including Sun Ray thin clients and protocols like RDP. It provides an example use case of Sun VDI deployment at the 2009 JavaOne conference supporting 20,000 desktops from clustered storage and server resources.