COSMIC Epoch 1.6 brings per-app audio and remote desktop groundwork

August 18, 2026. System76 released COSMIC Epoch 1.6, the latest iteration of its desktop environment written in Rust. The headline items: per-application audio — the most-requested feature — two recent Wayland protocols in the compositor, and the first building blocks of remote desktop. It ships no headline-grabbing feature, and that is exactly why it matters: COSMIC is moving from prototype to daily driver.

You can measure the distance traveled by what this release does not contain: no interface overhaul, no new paradigm. Just a dozen repositories bumped in sync, a set of annoying bugs crushed, and sound that is finally manageable at a fine grain.

Per-app audio, at last

The request had been sitting in the queue since COSMIC’s first alphas. On a typical desktop, volume is a global knob: one slider for everything, never mind if the browser is blaring while your video call whispers. COSMIC Epoch 1.6 adds per-application audio routing to cosmic-settings: every program gets its own level and its own output, straight from the settings panel.

It is a comfort detail, but it is the kind of detail that decides whether people actually live in a desktop. Nobody switches environments for a prettier window manager; they switch when the basics stop annoying them. System76 knows this: instead of stacking features, the team spent this release polishing what already existed.

The system tray’s volume slider shows the approach in miniature. It is now debounced by 128 ms so rapid volume changes no longer cause audio stutter. The launcher no longer flickers when you mash the Ctrl key. The terminal gains borders around split panes and context menus in its input field. Nothing flashy; everything that mattered.

Wayland matures, remote desktop takes shape

Under the hood, the most technical changes land in cosmic-comp, the Wayland compositor built on smithay. It now supports wl-dmabuf-v6, the current version of the GPU buffer-sharing protocol, and consumes presentation feedback from fullscreen surfaces — a concrete fix against tearing in games and video playback.

The more interesting signal is elsewhere: the compositor adds the EI (emulated input) protocol. That is not trivial. EI is the technical foundation for remote desktop: it lets a remote client inject input events in a standardized, secured way. Epoch 1.6 does not ship remote desktop yet, but it lays the first stone, alongside work already underway on the topic.

The logic fits System76’s strategy. Pop!_OS still ships GNOME today, but COSMIC is meant to replace it. A desktop destined for the professional machines System76 sells will eventually need to run a remote session properly — that is an enterprise prerequisite, not a toy. By upstreaming EI now, the team locks down that workstream before it even announces it.

Polish, not bloat

The rest of the release is a series of fixes, each of which had someone screaming. cosmic-files no longer freezes the session in an infinite dialog loop when mounting an SMB or NFS share fails. HiDPI glyph rendering is finally fixed, eliminating jagged text on high-density displays. cosmic-greeter now blocks empty passwords on accounts that require one, and detects logind at runtime, making it more at home in containers and minimal installs.

On the security side, cosmic-greeter also accepts JPEG-XL and AVIF image formats. The settings daemon stops panicking when a display reports a -1 maximum brightness, and it picks up AC plug events more reliably through upower.

The full list lives on the epoch-1.6.0 release page on GitHub, with the complete diff between 1.5.0 and 1.6.0. The repository still shows 1,800 open issues: COSMIC remains a work in progress, but one whose roadmap is now readable.

Why Rust, why a new desktop

Behind Epoch 1.6 sits a strategic bet. System76 sells Linux computers — the Thelio workstations, the Lemur Pro and Oryx Pro laptops — and could not stay tied to a GNOME whose roadmap it does not control. COSMIC is written in Rust on the company’s own libcosmic toolkit. The argument is memory safety. A desktop environment is an assembly of low-level code juggling buffers, window descriptors and shared memory regions; writing it in Rust removes at compile time a whole class of crashes and vulnerabilities that haunt C extensions.

The cosmic-comp compositor, built on smithay, is the heart of the project. Smithay is a Rust Wayland compositor library, and COSMIC is currently its largest production testbed. Every protocol COSMIC upstreams — wl-dmabuf-v6 for GPU buffers, EI for remote input, presentation feedback for synchronization — benefits the whole smithay ecosystem, not just System76. That is what makes the project interesting beyond Pop!_OS: it pulls a free library forward.

Then there is the calendar question. Pop!_OS still ships GNOME by default, and COSMIC runs alongside it; it becomes the primary environment when the team judges it ready. The repository still lists 1,800 open issues, and System76 frames the effort as a multi-year project. Epoch 1.6 does not change that trajectory — it just makes it more credible, one release at a time.

This release also confirms a steady cadence: epochs 1.4, 1.5 and 1.6 have landed within a few months, each carrying fixes rather than a rewrite. That is the rhythm of a project aimed at incremental stability — the mark of software meant to ship on machines people buy, not just tinker with on weekends.

Put this in the context of the wider desktop Linux landscape. GNOME and KDE Plasma dominate, but both carry decades of C and C++ heritage; COSMIC is the first serious attempt to build a full desktop stack in a memory-safe language from the ground up. The fact that Epoch 1.6 reads as a polish release rather than a feature dump is itself the news — the foundation is now stable enough that System76 can spend a cycle on jagged HiDPI text and a freezing file manager instead of fighting the compositor. For anyone waiting for a modern alternative to GNOME’s opinionated workflow, that is the signal to start paying attention.

Verdict

Epoch 1.6 confirms the trajectory: COSMIC is no longer a prototype, it is a desktop you can install in the morning and use through the evening. Per-app volume and the HiDPI fix remove the two irritants that used to send the curious back to GNOME after a week.

If you run Pop!_OS, take the update through the standard system updates: it is a net comfort win with little regression risk. If you run another distribution, the question stays open — COSMIC can be tried standalone from its GitHub repositories, but that is a bet on an ecosystem still under construction.

The decision criterion is simple: if your daily use is a browser, a terminal and a handful of Flatpak apps, COSMIC at 1.6 is already viable; if you depend on GNOME extensions or advanced desktop tooling, wait another two or three epochs. Either way, take the lesson of this release: the desktop that wins is not the one that adds the most — it is the one that finishes what it started.

References

• Phoronix, “COSMIC Epoch 1.6 Released With Per-App Volume Control, Remote Desktop Preparations”, August 18, 2026.
• Linux Compatible, “System76’s COSMIC Desktop Gets Wayland Upgrades and Per-App Audio in Epoch 1.6.0”, August 19, 2026.
• GitHub, “pop-os/cosmic-epoch”, release epoch-1.6.0, August 18, 2026.