Ubuntu 17.10 (Artful Aardvark) was the first Ubuntu release to ship with Wayland as default display server, while the XOrg session was put on the back seat. Now it looks like wants to play it safe for their next LTS (Long-Term Support) release, Ubuntu 18.04 LTS (Bionic Beaver), and decided to go with the old XOrg graphics stack by default for new installations. The decision to put Wayland on the back seat and ship with the Xorg graphics stack by default for Ubuntu 18.04 LTS was taken because screen sharing works well under Xorg with software like Google Hangouts, Skype, or WebRTC services, Remote Desktop services like VNC or RDP also work well under Xorg, and the recoverability from GNOME Shell crashes appears to be less dramatic under Xorg.