Parent's business provides virtual servers to the general public (disclosure: I'm a customer). With Xen, guests can run any distro kernel, self-compiled kernel

Parent's business provides virtual servers to the general public (disclosure: I'm a customer). With Xen, guests can run any distro kernel, self-compiled kernel with custom patches, or even BSD -- any guest kernel with Xen patches should work. The guests can update their kernel on their own, and the only the guest that's updating their kernel needs a reboot -- the host, and guests which don't change kernels except during major upgrades, can have months or years of uptime. So if you have a business where some of your customers want custom, bleeding-edge kernels, and others mainly value stable systems with high uptimes, and everyone wants to run a different distribution's kernel, then containers aren't for you. I guess I'm trying to say that VPS will always have a niche in the market. The parent lives in that niche. Containers offer fundamental resource-efficiency advantages and may capture large markets from Xen and Xen-like technologies over the next few years, but I disagree with the article's implication that Xen will eventually become extinct. As the parent notes, RAM is cheap, and the difference in costs between container and Xen will give the former an advantage, but never be big enough to drive the latter completely out of business, since the difference is small (on an absolute scale) and Xen can do a few things that containers can't.