We are pleased to announce the addition of COSMIC as a new Synex Semi-rolling edition. This edition joins those already available in the Debian testing-based branch (KDE Plasma, GNOME and XFCE) and ships COSMIC in version 1.1.0, the latest released by System76, positioning Synex among the first distributions to offer this updated desktop on a Debian base.
COSMIC, a next-generation desktop
COSMIC is the desktop environment developed by System76, written entirely in Rust and built on Wayland. Unlike traditional desktops, COSMIC does not rely on GTK or Qt for its core operation, but on its own toolkit (libcosmic), giving it a coherent visual identity and remarkable performance. Its design combines a window manager with optional tiling support, configurable panels and dock, and a flexible workspace system, intended for users seeking productivity without sacrificing a modern aesthetic.
The Synex edition incorporates version 1.1.0, which adds the system monitor (cosmic-monitor) as a new component and consolidates improvements in settings, the application store and the applet set compared to previous versions.
Synex identity in every detail
COSMIC on Synex is not a generic integration: the desktop adopts the project's visual identity out of the box, with no configuration required from the user. Synex's signature orange accent is applied system-wide, from the session manager to the environment's own applications, accompanied by the Inter and Hack typefaces, the wallpaper and the dock with Synex shortcuts.
The adaptation work also addresses consistency with third-party applications: GTK applications are displayed in a dark theme consistent with the rest of the desktop, avoiding the contrasts that often appear when integrating environments based on different toolkits.
Open and reproducible packaging
As part of this release, Synex publishes the cosmic-synex repository on GitHub, containing all the packaging work for COSMIC on Debian and Synex. The repository does not distribute COSMIC's source code, but the patches that adapt System76's official packaging to Debian (replacing Pop!_OS ecosystem dependencies that do not exist in Debian) along with the scripts that automate downloading, patching and building the packages.
This approach allows anyone to rebuild COSMIC for Synex reproducibly, audit the applied modifications or adapt them to their own needs. The repository is available at Github under the GPL-3.0 license.
Updated Semi-rolling base
Like the rest of the Semi-rolling editions, COSMIC is built on an updated Debian testing / Forky base. Among the main components are Linux kernel 7.0.12, systemd 261, OpenSSL 3.6.3, Mesa 26.1.2, PipeWire 1.6.7, WirePlumber 0.5.14, Firefox ESR 140.12.0 and Flatpak 1.18.0. The installer remains on Calamares with calamares-settings-synex 1.0.28, and Synex Package Manager is included in version 1.2.0.
Considerations
The Semi-rolling branch is intended for users who want more recent versions of the desktop environment, kernel and system components. Being based on Debian testing, it may receive more frequent changes than the stable edition and occasionally require adjustments between updates. In the particular case of COSMIC, it is a young desktop under active development, so evolving features may be found. For environments where long-term stability is a priority, the Synex stable branch remains the recommended option.
Availability
The Synex Semi-rolling COSMIC image is available for the amd64 architecture, alongside the KDE Plasma, GNOME and XFCE editions. As always, we recommend verifying the checksums of downloaded images before creating the installation media.
Download Synex Semi-rolling from here.