I think that using the term 'application containers' to reference docker and 'system containers' to reference LXC is a bit of a meaningless distinction.
You can 100% host "systems containers" on Docker and you can host "applications" on LXC.
Like if I want a entire OS with it's own init system and users and so on and so forth I can do it it OCI images.
In fact I use it every single day with distrobox on top of Podman using OCI container images.
And it works a hell of a lot better then if I tried to do it on LXC.
yeah, the system/application distinction feels somewhat superficial. The “multiple user space” inside a container thing sounds interesting (not sure what that means exactly), but maybe more similar to a Kubernetes pod, except maybe instead of different rootfs there’s another isolation mechanism?
You can 100% host "systems containers" on Docker and you can host "applications" on LXC.
Like if I want a entire OS with it's own init system and users and so on and so forth I can do it it OCI images.
In fact I use it every single day with distrobox on top of Podman using OCI container images.
And it works a hell of a lot better then if I tried to do it on LXC.