Quickemu is a command-line wrapper for QEMU that can be used to quickly create and run highly optimized Linux, macOS, *BSD, and Windows desktop virtual machines.
Instead of expecting an exhaustive list of configuration options, Quickemu tries to automatically “do the right thing” and creates the VM configuration automatically for you (though you can still tweak the settings to suit your needs). Besides this, the tool also automatically downloads the Linux, macOS, or Windows image, so all you have to do is run and install the OS in the virtual machine.