[menage]

Yes, we contributed the core cgroups system, and a good chunk of the memory and I/O cgroup subsystems. Google didn't have much need for namespacing though - when you have complete control over all the code that's running, it's possible to have the common libraries co-ordinating with the cluster management system to assign things like network ports and userids, so there's no need to virtualize IP addresses or userids. Google's containers are (or at least were - I left a few years ago) just for resource isolation.