… maybe not quite as popular as docker, but it conquered many other areas, for example build systems and more.
There's one facet nspwan is particularly good at: we use it to showcase new integration features between the host systemd and containers. nspawn for example natively supports propagating credentials down to its payload, or supports sd_notify() ready notfications for the service manager in the payload. It allows binding a host user into the container via --bind-user=, or…