Ubuntu founder Mark Shuttleworth wrote a blog post this week contemplating the possibility of making Ubuntu's new Unity shell work on the Wayland display system, with the aim of eventually shipping Wayland as Ubuntu's standard display manager. A transition of such enormous scope isn't going to happen in the near future, but it certainly can't hurt to start thinking about it now.

The X Window System (X11) is a cornerstone of graphical Linux computing. It is a display server that is responsible for showing graphics on the screen and mediating user input. The ubiquitous X.org implementation of the X Window System is included in all mainstream desktop Linux distributions. The problem with this venerable component of the Linux technology stack is that it was created in the 80s and hasn't been able to shed the superfluous accoutrements of yesteryear computing.

New capabilities are tacked on in extensions as needed, but the underlying architecture of X11 remains mired in antiquity because so many inextricable facets of its design are anachronisms. X11's network transparency, for example, was an asset in the hallowed days of thin-client computing, but is no longer a requirement for the vast majority of regular end users.

Although the Linux ecosystem would benefit greatly from a lighter and more easily extensible alternative, a concerted effort to displace X11 on the Linux desktop hasn't really emerged yet because the task of bringing drivers, third-party software, and all of the other layers of the stack into alignment with such a move would be prohibitively cumbersome. Like, in the sense that using only your toes to build a full-scale replica of he Statue of Liberty out of toothpicks is prohibitively cumbersome.

Shuttleworth contends that X11 isn't conducive to creating the kind of user experience that Canonical hopes to deliver in Ubuntu. His blog entry also points out that some of the classic strengths of X11 are already being compromised by decisions that are being made for the sake of user experience improvements. The implication is that it makes sense to take those compromises to their natural conclusion and give up on legacy features like network transparency in favor of delivering the best possible experience for regular end users.

"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," Shuttleworth wrote. "Some of the core goals of X make it harder to achieve these user experiences on X than on native GL, we're choosing to prioritize the quality of experience over those original values, like network transparency."

One of the most promising candidates for a next-generation Linux display server is an experimental project called Wayland that was created by developer Kristian Hoegsberg. It has a built-in compositor and is designed to take advantage of the latest advancements in Linux graphics technology. It's a very promising project, but it's still a ways away from being ready for adoption in the capacity that Shuttleworth aims to put it to use. Hardware compatibility is still limited because not all proprietary graphics drivers support the necessary features.

A gradual transition could conceivably be successful, however. It's possible to run a rootless X.org server inside of Wayland, which would functionally allow existing applications that aren't Wayland-enabled to continue running properly. In this hybrid approach, applications like Unity that would benefit from operating natively on Wayland can be adapted to so while the rest of the software stack continues operating as it always has without need of modification. Once the groundwork has been laid, the rest of the stack can be transitioned to Wayland incrementally.

Shuttleworth estimates that such a move would take at least four years, but he thinks that the effort would be worthwhile and that there are no alternatives that are better-suited than Wayland. Canonical aims to contribute to Wayland by bringing its multitouch focus to the project. Integrating multitouch capabilities in the current X11 ecosystem has proved to be non-trivial, so it could be beneficial to have such features incorporated at an early stage.

Don't expect to see X.org excised in the next release of Ubuntu. Adopting Wayland is a long-term effort, one that will be carried out in small steps. Even after Wayland is adopted, X11 will still be around for a long time for compatibility purposes (even Apple can't escape it entirely). I'm cautiously optimistic about the plan and I think that commitment from a major distributor is a promising sign.