&gt; And the first -- I&#x27;m not convinced that qemu and x86 is all that much more restricted than a well jailed process. Given the complexity of the PC, and the number of critical Xen&#x2F;KVM&#x2F;... vulnerabilities, it certainly isn&#x27;t trivial to emulate securely.<p>Xen has their own priorities and I have my views on their code quality. The interface is that much smaller that it should be much more possible to implement securely than the unix API (which isn&#x27;t even well-defined). People elsewhere are talking about seL4; I hope we&#x27;ll one day see a formally verified hypervisor. I don&#x27;t think we&#x27;ll ever see a formally verified unix container.<p>In the long run you&#x27;re right, there&#x27;s ultimately no difference between compiling my OCaml to a binary that runs on a secure formally verified microkernel and building it into a unikernel that runs on a secure formally verified hypervisor. But I can take steps towards the latter now - I can deploy unikernel systems to EC2 today, and while they may not be more secure than deploying processes to Joyent today, they&#x27;re using an interface that should make it possible to run them on a more secure environment.