Docker has always used microVMs (well since 2016)

Article title is a bit click-baity. The article is only talking about Docker Desktop on Mac or Windows. Docker Linux have not been using microVMs for a decade.

Its bending history to call what before were Linux Vms inside Mac or Windows to have containers to that is a real MicroVM.

And the current Sandboxes dont offer the same security model - See Docker Sandboxes 0.42.0 security update: CVE-2026-77179 and CVE-2026-79994

https://docs.docker.com/security/security-announcements/

> What if I told you that Docker Desktop has always used microVMs?

Then I would say your title is wildly misleading.

Is all of docker one “micro” VM though? Or does each container get a clean, fresh one?

One reason I think a distinction is made is that native Docker-in-Docker can be a real pain, but Docker in a Firecracker microVM "just works".

I often wonder what would have happened if rkt had been more successful.

Yawn. IBM/AIX's WPARs & LPARs, Sun/Solaris' dynamic system domains & zones, BSD jails. How many times are we going to pat ourselves on the back for reinventing the wheel?

...*on macOS only and runs qemu as the emulator.

We know. But of course the hype of "microVMs" is just a rebranding of existing technologies with some modifications, macOS needed extra virtualization technologies just for containers for years:

   Docker Desktop macOS (until 2025): QEMU + Virtualization.framework + Linux kernel (without extra drivers) = "microVM".

   Linux: KVM + Linux kernel (without extra drivers) = Firecracker "microVM".

[0] https://www.docker.com/blog/docker-desktop-for-mac-qemu-virt...