KvmCtl assists you in administrating KVM virtual machines. It doesn't provide a full management suite to fit all needs, it is just a little helper program to start, stop and check your virtual machines on a host.
As a little bonus, it can also list OpenVZ Containers running on the same host. This might be useful since KVM and OpenVZ play quite nicely together on the same host. However, KvmCtl is mainly targeted for KVM virtual machines and so doesn't offer any functionality for OpenVZ Containers other than listing. Use vzctl for containers, it can do almost everything already.
More information can be found on its GitHub page: