Ubuntu Core Desktop returns as Canonical’s plan for an immutable default desktop
Canonical has restarted work on Ubuntu Core Desktop, the immutable and attestable version of Ubuntu that the company says will over time become the default Ubuntu desktop. Jon Seager, Canonical’s VP of engineering, laid out the plan and admitted that the 2023 developer preview “fell short” of what the company had in mind.
On Core Desktop, everything ships as a snap, Canonical’s sandboxed package format: the bootloader, the kernel, the desktop environment, background services and every app. Immutable means the base system is read-only. Attestable means the machine can prove what software it is running. Defenders get a system that is harder to tamper with and easier to verify. Users get a desktop that runs only software packaged as snaps.
Daily images come first
Ubuntu Core has run on commercial IoT, embedded and robotics hardware for almost ten years, but the desktop version went quiet after 2024. Canonical has now set up a dedicated Core Desktop team and is rebuilding the pipelines that produce the images. “Over the coming weeks, we’ll have the infrastructure ready for continuous testing and daily image builds for Ubuntu Core Desktop,” Seager said. Canonical expects daily images during the Ubuntu 27.04 cycle.
Apps are the bottleneck
Canonical is starting with three kinds of machine: browser-centric systems, developer workstations and gaming machines. It picked those three because of app availability, which the company counts among its main blockers. If the software a team depends on does not exist as a snap, Core Desktop cannot run it. Other open problems include splitting the desktop into components that update independently, permission prompting, and supporting KDE Plasma alongside GNOME.
Classic snaps stay on the table
Permission prompting matters because of how snaps are isolated. A strictly confined snap can reach files and devices only through interfaces it has been granted. A classic snap runs with no confinement, much like a traditional package, and Ubuntu Core does not support classic snaps today. Prompting lets a user approve access for a confined app while it runs.
Seager said he intends “to build an ergonomic experience for those who want to use classic snaps” on Core Desktop.
Seager said today’s Ubuntu Desktop is staying. If you expect to evaluate Core Desktop, start with an inventory: which of your tools ship as strictly confined snaps, and which ship as classic snaps or not as snaps at all.
