Yes, even if it's "just a kernel", it's still an operating system. It's a piece of software that runs in the supervisor mode of the CPU, providing system call services to user applications.

The marketing copy appears, on this basis, to be somewhat misleading. It says on the site that this is a cloud where "multi-tenant containers can inherently be run safely side by side on bare metal, instead of being nested in VMs".

I think that, as an industry, we've established that "bare metal" execution of workloads means _without_ the multi-layered approach of a hypervisor (itself an OS) running a separate guest OS kernel.

So, yes, an OS. This isn't like a software isolated process in Singularity or little component in a user-mode runtime leveraging a L4-like microkernel. It's virtualization + a kernel + (maybe something here) + my code.

That's a stripped-down, guest OS on virtualized platform. Basically same sort of thing that's common but with some differentiator.

Does this kernel run its own TCP stack and filesystem?