Toro is just a library OS that allows you to build an application and deploy it as a VM without the OS. Toro acts as the OS. Different that other unikernels, Toro is not meant to be POSIX compliant. The idea is to provide an API that suits better the use-case, i.e., an app deployed as a VM. Toro can also run in baremetal although I dropped the support a few commits ago. I can roll back that support in case there is interest.