In docker-1.11 docker is going to be using a new daemon, containerd, as well as runc. However docker is forcing a link between containerd and runc. During the building of docker, docker is actually pulling the containerd and runc packages currently installed on the box and check summing them.
Then docker refuses to run unless these exact versions of containerd and runc are installed on the box. Docker does change the name of these executables to docker-containerd and docker-runc.
As we look to package these tools for Fedora, Centos and RHEL, we have to decide whether or not we want to package multiple versions of runc so that we can develop these at different rates or lock the versions together as docker wants. We could patch out the checksum check and rely on rpm to make sure the current version of docker has a late enough version of containerd and runc, to be supported.
Not sure what the policies of Fedora and Centos to have multiple versions of basically the same executable installed on the system at once.