Ganeti can use either Xen, KVM and LXC hypervisors -- I've actually only used the KVM backend.
I've used Ganeti Web Manager[0] in the past, but would probably try out Ganetimgr[1] for future installs. The command-line tools are very good however, and I don't think the web interfaces expose the full functionality (i.e. rebalancing, node evacuation, master-failover, etc).