UrsaOS

An Arch Linux–based rolling distribution with a curated Plasma desktop.

Download · Installation · Desktop · Support · Contribute

Important

v0.1.0-beta.3 is the current public prerelease ISO (Plasma). Active development targets Plasma as the permanent desktop. Packages are on repo.ursaos.dev and the ISO is on SourceForge. UrsaOS is not yet a stable production distribution.

UrsaOS combines a graphical Try & Install live system with curated desktop defaults, a signed package repository and an offline-capable Calamares installation.

Why UrsaOS?

UrsaOS keeps Arch's rolling package base and familiar tooling while providing a complete, preconfigured desktop:

• Plasma as the permanent Wayland desktop (Beta 3+), with one fixed look (UrsaOS Aurora)
• graphical Try & Install ISO with German and English live sessions
• Calamares live-copy installation that does not require a network connection
• Btrfs with an optimized subvolume layout and optional snapshots
• BearHub and BearWave as source-built UrsaOS packages
• signed UrsaOS package updates through repo.ursaos.dev
• carefully selected defaults without hiding the underlying Arch system

UrsaOS is not a fork of the Arch package tree and does not carry a complete offline Arch mirror. The tested live filesystem itself is the installation payload.

Desktop at a glance

Area	UrsaOS default (Plasma)
Base	Arch Linux, rolling release, systemd and Pacman
Desktop	Plasma (ursaos-desktop-plasma)
Login	SDDM with UrsaOS Qt 6 greeter
Look	UrsaOS Aurora (theme, decoration, Kvantum, cursors, BeautySolar icons)
Terminal	Kitty
Shell	Fish with Fastfetch, Starship and pkgfile command suggestions
Files	Dolphin
Software	Arch repositories, Flatpak, BearHub; Paru/AUR optional
Radio	BearWave (Qt 6)
Updates	notification-only checks; installation remains user initiated

Interactive Fish sessions show a branded UrsaOS system overview. The cat abbreviation expands to bat --style header,snip,changes without replacing the system's /usr/bin/cat.

Why Plasma?

UrsaOS started with Niri + Dank Material Shell (DMS) as its desktop. While Niri is an excellent Wayland compositor, DMS as a shell had significant gaps in everyday use: no integrated network profile editor, no user account management GUI, and limited file-manager integration. These gaps required constant patching and workarounds that were fragile across updates.

Plasma provides a complete, mature desktop environment out of the box — network management, user settings, Dolphin, Discover, System Settings — all maintained by a large community. This lets UrsaOS focus on curation and branding instead of filling basic desktop functionality. The Niri + DMS combination remains available as the final Beta 2 for historical reference; see docs/desktop-niri.md.

Screenshots

SDDM login with UrsaOS branding	Live desktop (Plasma Wayland)
Kitty + Fastfetch system overview	System settings — Über dieses System

System requirements

• x86_64 processor
• UEFI firmware and a GPT-capable installation target
• at least 2 GiB RAM
• at least 12 GiB free storage
• graphics hardware capable of running a modern Wayland desktop

Legacy BIOS/CSM installation is intentionally not supported. UrsaOS targets modern Wayland-capable systems and keeps one maintainable boot and install path.

Try and install

Download the current public image and matching checksum from the UrsaOS SourceForge files page. Release notes, tags and the checksum attachment remain available on the GitHub Releases page. Verify the download before writing it to a USB drive:

sha256sum -c ursaos-*.iso.sha256

Booting the ISO opens a deliberately text-based, firmware-compatible GRUB menu with two primary choices:

• UrsaOS starten — Deutsch
• Start UrsaOS — English

The selected language also configures the live keyboard layout. Console recovery and hardware utilities remain grouped under Advanced options / Erweiterte Optionen.

The live desktop runs as the temporary user ursa. Explore the complete desktop first, then start Install UrsaOS:

ursaos-install

Calamares copies the running live system to disk. The normal installation therefore remains available without an internet connection.

Installer choices

Choice	Default	Notes
Filesystem	Btrfs	Creates @, @home, @cache and @log subvolumes
Snapshots	Snapper	Timeshift or no snapshot manager can be selected instead
Kernels	Linux + Linux LTS	LTS is offered as a recommended additional kernel
BearHub	Recommended / standard	Graphical package manager on Plasma
Paru / AUR	Disabled	Explicit opt-in; retains base-devel and enables AUR checks

For expert users, ursaos-install-advanced keeps Archinstall available as an online fallback. It is not the primary or recommended installation path.

Detailed guides: installation, Plasma desktop, Plasma ISO build and updates.

Included UrsaOS components

• ursaos-base — identity, Pacman configuration and shared CLI defaults
• ursaos-desktop-plasma — standard Plasma stack, SDDM greeter, curated apps
• ursaos-plasma-theme — UrsaOS Aurora look (style, decoration, Kvantum, cursors)
• ursaos-kara — workspace pager plasmoid
• ursaos-installer — Calamares configuration and target cleanup
• ursaos-keyring — package-repository trust
• ursaos-update — manual updater and notification-only update checks
• ursaos-bearhub — graphical package manager (source-built, e.g. 0.10.8)
• ursaos-bearwave — internet radio (source-built, e.g. 1.3.0)
• ursaos-icons-beautysolar — icon theme for Plasma
• ursaos-paru — optional AUR helper
• ursaos-desktop-niri / ursaos-dms-shell / DMS integrations — final Beta 2 only

Official UrsaOS packages are distributed through the signed repository at https://repo.ursaos.dev/x86_64. Package signatures are mandatory. Flatpak is installed by default; AUR packages remain unsupported, user-maintained third-party software and are never installed automatically by UrsaOS.

Updates

UrsaOS periodically checks for repository updates and displays a desktop notification when updates are available. It never installs them silently. Start Update UrsaOS from the application launcher or run:

ursaos-update

The update uses one complete pacman -Syu transaction and requires normal sudo authentication. AUR checks occur only after the separate Paru/AUR opt-in during installation or an explicitly requested one-shot check.

Build from source

On an up-to-date Arch Linux build host:

sudo pacman -Syu --needed archiso git base-devel pacman-contrib cargo go \
  extra-cmake-modules libglvnd ninja python python-build python-installer \
  python-setuptools python-wheel qt6-tools qt6-translations \
  kcoreaddons kcrash kpmcore libpwquality qt6-declarative qt6-svg yaml-cpp

./scripts/validate-profile.sh
./scripts/build-package.sh all
sudo rm -rf /var/tmp/ursaos-iso-work
sudo ./scripts/build-iso.sh plasma

The ISO is written below out/ together with its .sha256 file. The mkarchiso work tree must remain on a local filesystem, not NFS or CIFS. See docs/build.md for the complete build and validation workflow. Publish signed packages with ./scripts/publish-repo.sh.

Project status

The current public prerelease ISO is v0.1.0-beta.3 (Plasma). Its ISO and matching checksum are hosted in the SourceForge Beta 3 folder.

In-tree and on repo.ursaos.dev, development continues on the Plasma standard stack: SDDM greeter, UrsaOS Aurora look, Kara, BearHub 0.10.8, BearWave 1.3.0 and the Plasma metapackage — see docs/roadmap.md.

Every release candidate must pass the complete release checklist as one coherent artifact: live boot, clean Calamares installation, reboot, login, desktop startup and package update.

Known scope boundaries:

• no legacy BIOS/CSM installation
• no stable-release or production-support guarantee yet
• AUR software is outside Arch and UrsaOS support
• hardware-specific Wayland and driver issues may still require investigation

See CHANGELOG.md for release changes and docs/roadmap.md for planned work.

Contributing and support

• CONTRIBUTING.md — development workflow and required tests
• SUPPORT.md — support scope and useful bug reports
• SECURITY.md — private vulnerability reporting
• CODE_OF_CONDUCT.md — participation standards
• RELEASE_CHECKLIST.md — release gates

The name comes from Latin ursa (bear) and connects UrsaOS to the independent BearWave and BearHub projects without reusing their application names for the distribution.

License

Unless stated otherwise, original UrsaOS material is GPL-3.0-or-later. Third-party components keep their own licenses; see LICENSING.md.