Ubuntu 18.04 LTS Will Default To The X.Org Stack, Not Wayland

While Ubuntu 17.10 defaults to using the Wayland session on supported GPUs/drivers when using the default GNOME Shell based session, Canonical has decided for Ubuntu 18.04 "Bionic Beaver" LTS that it will use the X.Org Server by default.

The GNOME Wayland session will still be available for those interested, but Ubuntu 18.04 with GNOME will default back to using X.Org rather than Wayland. The Wayland session will remain from the GDM log-in screen.

Among the expressed reasons for Canonical deciding to switch back to X.Org for this Long-Term Support release is for better screen sharing support in applications like Skype and Google Hangout, remote desktop control working better for now with X.Org, and the GNOME Shell generally recovers better right now when crashing under X.Org rather than Wayland.

The GNOME Wayland session has been working on improvements for these current shortcomings, with efforts like PipeWire and further protocol extensions, but not in time for the April release of 18.04 LTS. Not expressed as a reason but also motivating for some is the NVIDIA Linux graphics driver working better under the X.Org Server with their Wayland support being limited to EGLStreams.

Canonical's Will Cooke confirmed the decision to switch back to X.Org via this post on the Ubuntu web-site this morning. At least they aren't trying to switch to their Mir Wayland support by default or anything like that for Ubuntu 18.04, which will be conservative with its changes due to being an LTS release.

Sadly though with this X.Org decision, Ubuntu 18.04 LTS will still be using X.Org Server 1.19. X.Org Server 1.20 has a lot of new features and improvements, but with it being delayed and no signs of releasing in the very near future, it will not make the cut for an Ubuntu LTS release on short notice.

Other prominent packages for Ubuntu 18.04 LTS targeting are the Linux 4.15 kernel, Mesa 18.0, and GCC 7.