This guide will teach you how to create and manage a VM in KVM using virt-install, virsh, and virt-viewer, which all make use of libvirt. For a beginner's guide and introduction to libvirt and virtualisation concepts, and why you would even want to use libvirt instead of, say, Virtualbox, see: https://jamesnorth.net/post/qemu-guide
CrossOver is CodeWeavers' commercial implementation of WINE and a dozen other components. It's a stable version of WINE with a proprietary graphical interface and a variety "hacks" that can get specific programs working, that wouldn't make it into WINE proper as they aren't long-term solutions. It aims to make installing, managing, and running applications easy. However, there are some issues with the user interface.
Here's the scenario: your laptop is approaching 13 years of age, the internal NIC has suddenly stopped working, but you don't want to give up here. You uninstall Arch Linux and install Windows 10 just to check that the NIC is actually not functioning anymore—which it isn't. You buy a USB Wi-Fi NIC Adapter, carelessly not checking if the vendor's drivers have been mainlined into the Linux kernel. You boot into an Arch Linux live session and you don't have an internet connection. Here's what you do next.
It involved a fair amount of research to figure out how to setup and use virt-manager, virt-viewer, and even understanding what QEMU/KVM/libvirt are and what they do. This is as much a reference for me as I hope it to be helpful for others looking to use these technologies.
As a long-time user of Windows and macOS, I've long felt that these systems continually get in my way and slow me down. Windows has its own flaws, but I want to pick on macOS, because it's remarkably similar to GNOME without being nearly as usable, coherent, or efficient. Options are often taken away from you and hidden in obscure locations, or otherwise completely disabled. macOS is very opinionated, as all great desktops are, but I think you'll agree with me that at least some of the decisions are poorly thought-out or limiting for no good reason. Some, even, are relics of a different century that have never been rethought. While I have tried to do things the way Apple thinks I should, I don't think I'll ever be able to call it efficient or powerful—not in the same way I feel GNOME is. Some things simply can't be mended, even if they are seemingly trivial. There are certainly nice things about the desktop not present in Windows, but there are issues not present on GNOME that continue to eat away at me.