[dozzie]

Well, four years is what Wikipedia states.

I don't think there was anything as prominent as Docker on cgroups that was as old as ten years, since cgroups are that old. LXC was started eight years ago, and then Docker hijacked the subsystem and nomenclature.

But maybe you were thinking about some predecessor, like Virtuozzo/OpenVZ or Linux VServer? Those were never as popular in general public as Docker, but they had their mindshare, especially in some circles.