OpenVZ was an early container implementation that required patches to the Linux kernel that never made it into mainline. Parallels acquired the company behind OpenVZ, Virtuozzo, and then worked to mainline much of the functionality into what are now Linux namespaces.
Correction. The LXC project was mainly Daniel Lezcano and Serge Hallyn from IBM. Then some cgroup support from Google. And then Canonical hired Serge Hallyn and Stephane Graber to continue work on LXC around 2009 where they have continued to develop it till today. Docker based off LXC in 2013.