Many of you are already familiar with server virtualization and VDI and you might be looking for a virtualization approach that will help more easily secure and control desktop environments in a wider range of environments, i.e. bring-you-own-laptop, offline access, remote employees, etc.

Consider an alternative approach to VDI: instead of running the VM image on a centralized server, the VM is running locally on the end-user's machine. The mantra is: "Manage centrally, execute remotely." This new model provides a great platform for IT organizations to customize solutions to fit their needs.

First, let's look at application virtualization and how that might fit in. Some of you maybe familiar with it - the big names in this space are: Microsoft AppV (formerly SoftGrid), VMware ThinApp (formerly Thinstall), and Citrix XenApp. In this model, an application is packaged up in a bundle and the user runs the application from this bundle in a sandbox environment on their unmanaged desktop. This is a great solution for delivering single applications to users because the application does not need to be installed manually on the local machine and it is delivered on-demand to the user. IT does not get involved in managing the OS and data on the machine.

However, not managing the OS or the rest of the desktop makes the computing environment vulnerable. In most cases, it's imperative to properly manage the environment to make sure the computer doesn't crash due to a missing security patch or that business data is not left unsecured. This is one of the reasons the desktop virtualization approach "manage centrally, execute locally" really shines - by easily securing the environment around a virtualized application.

Source: http://blog.mokafive.com/2009/06/building-flexible-yet-secure-desktop.html