Control groups (cgroups) are a kernel mechanism for grouping, tracking, and limiting the resource usage of tasks. The kernel-provided administration interface is through a virtual filesystem. Higher level cgroup administration tools have been developed, including libcgroup and lmctfy. Additionally, there is guidance at freedesktop.org for how applications can best cooperate using the cgroup filesystem interface (see Resources).
As of Ubuntu 14.04, the cgroup manager (cgmanager) is available as another cgroup administion interface. It's goal is to respond to dbus requests from any user, allowing him to administer only those cgroups which have been delegated to him.