PC operating systems are full of security holes, which is why some are now turning to software first developed for 'hidden' computers to better protect them; Chris Edwards reports on what the enterprise computing can learn from embedded systems. Embedded systems, particularly in the military and avionics world, have used software-enforced separation for years using various forms of virtualisation. The control computers on many modern aircraft will let different operating systems share access to one processor under the control of a hypervisor that will only let each run within a specific time slot. The components can only communicate with each other through the hypervisor, and only if they have the right access privileges.