That Quine thing probably uses almost none of the Linux kernel API. Some of the language runtimes do some interesting things, but even fancy ones like V8 are no

That Quine thing probably uses almost none of the Linux kernel API. Some of the language runtimes do some interesting things, but even fancy ones like V8 are not that challenging in terms of kernel APIs. So I don't know anything about Illumos Linux zones, but if they run rr or docker or Firefox or WINE I'll be stunned. (Note that Firefox, rr and docker (by default) use seccomp-bpf syscall filtering which would be an absolute beast to implement in your Linux compatibility layer.)