I suspect it's more likely an immediate response to https://github.com/kubernetes-incubator/cri-o

People still want to use runc because it's a great piece of battle tested kit but don't want the kitchen sink and projects like CRI-O and Garden-Runc/Guardian are pushing the much simpler, smaller surface area angle.

Yes, I agree runc is a solid piece of kit. The rkt team is starting to use runc inside as well and hope to enable that in forthcoming releases to stay close to the Open Container Initiative specs as they move to 1.0. You can read more about that on our recent update post[1] or see a demo from a recent meeting[2].

Overall I appreciate all of the discussion on architecture of these systems and nailing this stuff down into the right format. My end goal is to ensure people get a strong reliable system, the exact technologies and projects used to get there is less important.

[1] https://coreos.com/blog/rkt-and-kubernetes.html [2] https://www.youtube.com/watch?v=x84Nes2P3Z4&t=124s

IF this announcement is all it seems, and I am expecting CoreOS folks to find any real trouble spots, this makes the various options at the lower-part of the stack much more similar.

OCI and runc were both largely responses to rkt as well, so that is pretty much variations over the same theme.