It's pretty clear that Docker has been focused on moving downstream. They want to add value by assembling open-source components into a complete platform that they can control and sell. They don't want to be the ones developing all the components themselves - at this level of maturity and sophistication in the container market, they just don't have the manpower to do that. A major benefit of that strategy is that they can use the best component available, regardless of who developed it. I bet they're feeling spread very thin on the open-source side, and would love to redirect some of their resources away from developing a gazillion open-source gadgets on their own, and towards their commercial products (which historically have been not as good in my experience).

Evidence that Docker is doing this:

- They only advertise three things with the name Docker: "Docker for Mac" (a free product that is not open-source), "Docker EE" (an enterprise product), and "Docker Hub" (a cloud service). Those are all downstream products, like RHEL or Openshift.

- The whole "Moby" thing is basically their upstream brand, aka "the things not called Docker".

- They spun out tons of smaller projects like buildkit, linuxkit, containerd, runc, and seem eager to get others to use them and contribute, even competitors.

- They embraced Kubernetes as part of their downstream product, even though they famously did not invent it, and they certainly don't control it.

So I think people saying "these free open-source tools are killing Docker" are missing the point. The real competition for Docker is Openshift vs Docker EE, everything else is implementation details.

If you listen to the sales pitch of these two companies right now, it's an absolute tug of war. Docker focuses on independence and innovation ("we know where containers are going, and we don't force RHEL down your throat"). Red Hat focuses on maturity and upstream control ("We've been by your side for 20 years, are you going to trust us or some Silicon Valley hipster? Also we employ more Kubernetes contributors than anyone else").

That's the real battle, in my experience on the open-source side you'll find mostly engineers from all side collaborating peacefully and building whatever they need to get their job done.

Although Docker images are not hard to build, (it is just a layers of tars with proper jsons) it is very nice to see such tools rise. Although I have a nice Kubernetes cluster, or any orchestrator, due to security reasons, I have to come up with a new VM with Docker installed and build it there, which really sucks. It is sad to see Docker did not implement this years ago although people wanted it a lot. They were busy deprecating the Swarm Whatever^TM for the 3rd time and not listening as usual.