[Jtsummers]

No, it's using a modified version of the Xen hypervisor and the numbers they show are boot times and memory usage for both unikernels and pared down Linux systems (via tinyx). It's described in the abstract:

> We achieve lightweight VMs by using unikernels for specialized applications and with Tinyx, a tool that enables creating tailor-made, trimmed-down Linux virtual machines.