What are some alternatives?
When comparing virt-manager and Virtualizor, you can also consider the following products
VirtualBox - VirtualBox is a powerful x86 and AMD64/Intel64 virtualization product for enterprise as well as...
Proxmox Virtual Environment - Proxmox VE is an open-source server virtualization platform to manage KVM virtual machines, LXC, software-defined storage and networking, HA clustering, and multiple other out-of-the-box tools on a single solution.
QEMU - QEMU (short for "Quick EMUlator") is a free and open-source hosted hypervisor that...
oVirt - oVirt is a virtualization management application.
VMmanager - VMmanager is a virtualization management software, which presents a perfect tool for creating virtual machines, providing VPS services and building cloud infrastructure.
Parallels - Parallels Desktop is a virtualization software for Mac users to run Windows and Linux apps on OS X.