System76 shipped COSMIC Epoch 1.3.0 on July 14, 2026 — the third minor update to its from-scratch Rust-based Linux desktop environment, and the release that finally delivers the visual centerpiece users have been requesting since the project launched.
The headline is frosted glass: a softly blurred transparency effect applied to window surfaces, panels, applets, and system interfaces. But the implementation goes deeper than a toggle — it's granular enough to enable selectively. You can enable frosted glass on the panel and dock while leaving application windows opaque, or go all-in across every surface. The setting lives under COSMIC Settings → Desktop → Appearance → Style.
Not a Reskin — A Different Codebase Entirely
Understanding why COSMIC matters requires understanding what it isn't. It's not GNOME with a theme applied. It's not a KDE fork. System76 built COSMIC entirely in Rust using its own custom toolkit, libcosmic, starting from nothing in 2022. That choice gives it a different performance profile from the rest of the Linux desktop landscape — faster cold-start times, more predictable memory usage — in exchange for a smaller extension ecosystem and fewer ready-made components.
1.3 continues that trajectory with two structural changes: the replacement of COSMIC Settings' custom NetworkManager backend with nmrs, a Rust-native alternative, and updates to the COSMIC Launcher to show the discrete GPU by default in the context menu.
GPU Monitoring Across AMD, Intel, and NVIDIA
The other major 1.3 addition is deeper hardware monitoring. The telemetry layer now exposes power draw, temperature, and utilization across all three major GPU vendors — AMD, Intel, and NVIDIA — surfaced directly in the COSMIC system interface without requiring a separate tool. For a desktop environment that positions itself partly at developers and creators pushing hardware, this is a more useful day-to-day feature than it might seem at first glance.
AVIF Wallpaper Support
A quieter change worth noting: COSMIC 1.3 adds AVIF wallpaper support via libdav1d. AVIF compresses images significantly better than PNG or JPEG at the same quality level — noticeable on HiDPI displays where a single wallpaper at native resolution can be several megabytes in older formats.
What's Still Missing
COSMIC's extension and theming ecosystem remains thin compared to KDE Plasma, and the app library is still catching up to what most users expect from a daily driver. For workflows that depend on complex tiling rules, third-party applets, or deep customization, it still requires more manual work than the established desktops.
That said, the gap has closed with each release. COSMIC 1.3 is available now via System76 software repositories and will roll into Pop!_OS with the next update cycle. Users on other distributions can build from source via the cosmic-epoch GitHub repository.