I also have to wonder just why they are trying to implement yet another flavor of containers for Linux. The mainline has LXC but many people see that as a bunch of zombie parts people are making a monster out of. In the out-of-tree category there are Linux-VServer and OpenVZ... which are both very complete and mature container implementations that are released under a GPLv2 license. Both Linux-VServer and OpenVZ started life outside of the mainline kernel and grew and developed to big and mature such that they are never going to make their way into the mainline.
Anyway, I'm not sure what CloudLinux uses... but I would imagine bits and pieces of at least one of those, right? Or have they really created a completely new flavor of containers?