After nearly three years of development, Invisible Things Labs has finally released Qubes 1.0, a Fedora 17-based Linux distribution that tries to be as secure as possible by isolating various applications in their own virtual machines using Xen. If one of the applications is compromised, the damage is isolated to the domain it’s running in.
While Qubes is based on Fedora, the fact that it runs the Xen hypervisor and creates a couple of virtual machines means that it inevitably uses more resources. Indeed, Qubes requires a 64-bit processor, and the developers recommend 4GB of RAM, 20GB of disk space and a fast SSD. If your processor features Intel VT-d or AMD IOMMU technology, driver domains such as those for the network and USB devices are isolated, which makes for an even greater level of security.
Rest here