Skip to main content

🌌 COSMIC Desktop on TunaOS

COSMIC is a modern, Rust-based desktop environment by System76 — the team behind Pop!_OS. Built from the ground up in Rust with the iced GUI toolkit, COSMIC offers a fresh, performant desktop experience on Enterprise Linux.

TunaOS ships COSMIC on all base OS variants.

Available Images​

Pull any of these COSMIC variants:

# Yellowfin (AlmaLinux Kitten 10)
ghcr.io/tuna-os/yellowfin:cosmic
ghcr.io/tuna-os/yellowfin:cosmic-hwe
ghcr.io/tuna-os/yellowfin:cosmic-gdx

# Albacore (AlmaLinux 10)
ghcr.io/tuna-os/albacore:cosmic
ghcr.io/tuna-os/albacore:cosmic-hwe

# Skipjack (CentOS Stream 10)
ghcr.io/tuna-os/skipjack:cosmic

# Bonito (Fedora)
ghcr.io/tuna-os/bonito:cosmic

Quick Start​

Switch to a COSMIC variant:

# From an existing TunaOS installation
sudo bootc switch ghcr.io/tuna-os/yellowfin:cosmic
sudo systemctl reboot

Or install fresh from the ISO — select "COSMIC Desktop" from the desktop picker.

What Makes COSMIC Special​

  • 🦀 Built in Rust — memory-safe, fast, and modern. One of the first full desktop environments written in Rust.
  • 🎨 Tiling + Floating — hybrid window management. Press Super+Enter for a terminal in tiling mode, or drag windows freely.
  • ⚡ Performant — lightweight and responsive, even on older hardware.
  • 🔧 Highly Configurable — panel, dock, workspaces, and keybindings are all customizable through a settings app.
  • 🌙 Built-in Dark Mode — system-wide dark/light theme toggle.
  • 🧩 Extensible — applets and extensions via the COSMIC applet system.

First Look​

When you first boot COSMIC:

  1. Welcome dialog — choose your layout (tiling vs floating default)
  2. Workspaces — dynamic workspaces on the left. Press Super+PageUp/Down to switch.
  3. Panel — top bar with app menu, system tray, and clock. Left side: workspaces. Right side: system indicators.
  4. Dock — bottom dock with favorite apps. Auto-hides in tiling mode.
  5. App Launcher — press Super+Space to open the launcher. Type to search.

Customization​

Appearance​

# Open Settings → Appearance
# Change theme: Dark, Light, or System
# Adjust accent color
# Toggle transparency effects

Keybindings​

ShortcutAction
Super+EnterOpen terminal
Super+SpaceApp launcher
Super+DShow desktop
Super+Left/RightTile window
Super+Shift+Left/RightMove window to workspace
Super+PageUp/DownSwitch workspace
Super+QClose window
Super+FFullscreen

COSMIC Settings​

The COSMIC Settings app (pre-installed) provides deep customization:

  • Desktop — wallpaper, dock behavior, hot corner
  • Panel — position, clock format, applets
  • Window Management — tiling gaps, focus follows mouse, minimize/maximize
  • Input — keyboard shortcuts, mouse/touchpad, gestures
  • Notifications — do not disturb, per-app notification settings

Software​

COSMIC runs standard GTK and Qt apps alongside native COSMIC apps. Install software normally:

# Flatpak (pre-enabled)
flatpak install flathub org.mozilla.firefox

# Homebrew (pre-installed)
brew install neovim

# COSMIC native apps will appear in the app launcher automatically

Tiling vs Floating​

COSMIC's hybrid approach lets you use both modes:

  • Tiling mode — windows auto-tile. Press Super+Enter to open a terminal in a new tile.
  • Floating mode — windows behave traditionally. Drag and resize freely.
  • Mixed — some windows float (dialogs), others tile. Configure per-app in Settings.

Toggle between modes from the panel or with Super+Y.

Troubleshooting​

ProblemFix
COSMIC doesn't startEnsure GPU drivers are loaded: lspci -k | grep -A 2 "VGA"
Tiling not workingCheck Settings → Window Management → Tiling is enabled
App launcher slowThis is normal on first launch. Subsequent launches are cached
Missing COSMIC appletsRun cosmic-applets --version to check; reinstall if needed

See Also​