KaOS 2025.09 is the latest ISO snapshot of this independent, rolling-release Linux distribution that is singularly focused on providing a clean, current KDE Plasma desktop experience built exclusively with the Qt toolkit. The distribution is built from scratch with its own in-house repositories, using the familiar pacman package manager, and is a Qt6-only default installation, marking a significant step in modernizing the entire system stack. This release features the newest KDE software, including the Plasma desktop environment, KDE Gear, and KDE Frameworks, all running on a modern core stack, with the Calamares installer offering robust file system choices like XFS, EXT4, Btrfs, and ZFS.
The major change in KaOS 2025.09 is a complete overhaul of the visual experience and a final transition to Qt6 components. The default Midna theme has received a comprehensive refresh with a new icon set, updated login and splash screens, and a modernized color scheme and window decoration. Under the hood, the entire system is built with Plasma 6.4.5, Linux kernel 6.16, and a fully Qt6-based core, which involved replacing the VLC-based Phonon backend with phonon-mpv due to VLC’s lack of a Qt6 port. Additionally, the release introduces early support for the Plasma Login Manager as a potential replacement for SDDM, brings new default applications like Kjournald for log viewing, and updates the Calamares installer to use a QML drawer instead of a root-run web browser for displaying extra information.