The X Server which has been powering almost all the Linux distributions through the ages isn't good enough for Mark Shuttleworth.

"But we don’t believe X is setup to deliver the user experience we want, with super-smooth graphics and effects. I understand that it’s *possible* to get amazing results with X, but it’s extremely hard, and isn’t going to get easier."

Instead, over the next few years they will be transitioning to the Wayland display server. Which looks pretty young, to say the least.