Can someone provide an explanation as to the benefits and any consequences of using VirtualBox with BOINC? For example, I assume VB provides application sandboxing but also uses more system resources. What are the science apps that are using it & why? Or, does BOINC run all apps in the VM for security purposes? Does VB affect access to GPUs? Will it run the screen saver? Is it running a linux distro?

http://en.wikipedia.org/wiki/VirtualBox#Emulated_environment answers most of that.
GPUs can not be used, as the VMs only use a VESA compatible virtual graphics card (with a max of 128MB RAM).
Screen savers can be used.
Which leaves http://boinc.berkeley.edu/wiki/VirtualBox for the left-overs. BOINC will run all applications for a given project using VBox in the VM. The VM image is sent to you by the project. It uses mostly Scientific Linux.

As to why?
David Anderson wrote:

We recommend BOINC + VBox because we want there to be a large pool of volunteer hosts with VBox installed.
That will make it feasible for projects to deploy VM apps, which will make it easier for projects to deploy apps in general.

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Thanks. Can I suggest that you add http://boinc.berkeley.edu/wiki/VirtualBox to the download page? Also, I assume if I already have VB installed then BOINC will find it so I don't need to download the VB version of BOINC?

I have no say over what goes on the download page, and all the suggestions I gave the developers on this have gone in the wind, so far. I'll keep adding to the VirtualBox page, as and when I find more information.

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