OpenVZ (because it's closer to bare metal performance), which limits it to Linux distributions currently. We've had requests for FreeBSD though, and we're adding Xen support soon which should allow that.
FreeBSD on top of Xen has limitations (such as only one virtual CPU (AFAIK)) and in my testing is really unstable. Would you consider using something like KVM instead which has less issues?
It's definitely possible. We're not wed to any particular container/virtualization system. Networking tends to be a bit of a tricky issue, but I'll definitely check out FreeBSD on KVM. Thanks for the heads up.
