Karton, KDE’s in-progress virtual machine manager, continues to move forward with several new updates as of August 2025. For the uninitiated, the project, still not feature-complete, aims to deliver a Qt-native alternative to GTK-based tools widely adopted among Linux users, such as GNOME Boxes and virt-manager.
According to Derek Lin, Kartoon’s lead developer, one of the most important changes in this cycle is the removal of the dependency on virt-install. Instead, it now generates libvirt domain XML directly, using libosinfo to identify the installation media and fill in the required configuration details, such as UUIDs, MAC addresses, and virtual hardware setup.
Another big focus has been the move away from relying on virt-viewer. In light of this, Karton now includes its own SPICE client and viewer built with Qt. It handles display rendering, input forwarding, and audio streams, with support for fullscreen and basic resizing. However, performance and scalability still require improvement.
On the UI side, the VM list has been relocated to a sidebar, with detailed information and preview images displayed on the right. Additionally, Karton now saves the last VM frame on exit, allowing users to quickly identify machines before launching them again. A new media disc ejection option was also added, making it possible to remove installation ISOs once a system is set up.
According to Lin, during testing, the tool successfully installed and ran a Fedora KDE virtual machine, switched from installation media to the virtual hard disk, and ran applications within the guest. Disk management and advanced features, such as snapshots, remain on the roadmap.
There’s still quite a bit left to get done from here on out. The developers plan to enhance display performance with SPICE gl-scanout, introduce improved scaling, support file transfer and clipboard passthrough, and ultimately provide full snapshotting capabilities. Packaging as a Flatpak and inclusion in the KDE namespace are also being discussed.
For now, Karton is still considered experimental, and all signs indicate that things are moving in the right direction. Once everything’s ready, however, KDE users will finally be able to move on from depending on virt-manager. Honestly, it’d be great to see more KDE developers back Lin’s work, because Karton really has what it takes to become one of the key applications in the KDE ecosystem.
For more information on the app’s progress, see the announcement on the KDE blog.
Image credits: KDE Project
