I've been using Docker since forever and I think I grasp the architecture here. But, my question is, what does this bring to the table that isn't possible with

I've been using Docker since forever and I think I grasp the architecture here. But, my question is, what does this bring to the table that isn't possible with Docker + Machine + Swarm? That's a super important question to ask, because adding another layer to deployments is not something people are wont to do to a system (Docker) that's supposed to put the simplicity back into deployments. Also, since this isn't under Docker Inc.'s umbrella people would be right to be cautious depending on it lest it die, whether that's fair or not. I don't use CoreOS but I get it: it offers orchestration whistles that solve some people's problems. I also don't use but I understand PaaSes like Flynn: they're solving problems at a completely different layer and their ties to Docker are incidental. But this, the primary touted advantage seems to be that it's a slim Docker image. For me (and I imagine others) that is a solved problem with Machine and/or boot2docker. On top of not imposing any new overarching architecture to learn, those tools are already widely deployed, supported, and trusted, and have the huge unfair advantage of being blessed by Docker core. And if you really want to run Docker in Docker, that's been supported for a very long time, and you get that for free without installing anything. So I'm at a loss to think of a case I'd advise someone to reach for this. Is there something I'm missing?