This document discusses Citrix XenDesktop 4, which provides hosted virtual desktops and application delivery. It allows organizations to provision desktop operating systems, applications, and user profiles on demand from a single golden image. This reduces management costs compared to physical desktops. XenDesktop 4 provides a flexible approach, with support for virtual desktop hosting on XenServer, Hyper-V, VMware, and blade PCs. It includes features like profile management, smart card support, 3D graphics, and HDX technologies to optimize the user experience. The full XenDesktop 4 platform has components like XenApp and Provisioning Services to manage applications and desktop images respectively in an integrated virtual desktop infrastructure solution.