nspawn containers are yet not really used as a platform target, and currently Docker is leading. Though nspawn has since acquired some notion of the Docker image format, and even in light of the OCI standard, I do not foresee it becoming a primary container solution in its present form. rkt being nspawn-based may or may not take hold.<p>Indeed, systemd is as of yet not comprehensive enough to be a POSIX-parity target. There is no &quot;systemd Linux&quot; as such, it&#x27;s systemd&#x2F;GNU&#x2F;Linux or Linux with the GNU and systemd suite. Android is a top-down integrated system on the other hand and does not linearly track GNU&#x2F;Linux.<p>As of yet, there is nothing like system call emulation or similar in nspawn to have branded zones.<p>Nor does Red Hat&#x27;s present actions imply something like this. The GNOME project, affiliated with Red Hat, is working on a poor reinvention of Nix called xdg-app to enable the &quot;app frameworks and runtimes&quot; design that Lennart Poettering wrote about in &quot;Revisiting How We Put Together Linux Systems,&quot; but that too is firmly specific to GNU&#x2F;Linux as the host.<p>Red Hat is also leading a container OS called Project Atomic, however nothing like branded zones is seen there as a goal, either. Instead, they&#x27;ve made a simple meta-framework for running various <i>Linux</i> container images over several orchestration frameworks and PaaS, called Nulecule. It&#x27;s firmly a layer over Docker and Kubernetes, however, so it is limited to that.<p><i>A Linux &quot;ReactOS Runtime&quot; equivalent to Windows&#x27;s &quot;POSIX Runtime.&quot;</i><p>That would be quite a feat in of itself, systemd or branded zones aside. ReactOS isn&#x27;t Wine, but even with Wine it would be a sizable integration effort.<p><i>If that init daemon is effectively a container-manager that understands how to instantiate and manage different &quot;branded containers&quot; for each runtime it supports, Linux multi-runtime support just falls out.</i><p>The init daemon is not a container manager in this case, but an object-oriented resource management with a transactional job scheduler and some limited execution environment modification that work with namespaces and cgroups, but the container framework is outside. As it should be. An init daemon as your container manager sounds dreadful and horrifying, though I hear RancherOS boots from Docker as PID1...<p>But as there is no such init daemon yet nor anything like branded zones, I still have to say you&#x27;re a dreamer. This <i>might</i> be a long-term strategy, but with acts like Project Atomic it really doesn&#x27;t look like it. I still think it&#x27;s more middleware than Core runtime. I pray it is...