Kubuntu
Kubuntu is a free, user-friendly Linux distribution based on KDE's desktop software and on the Ubuntu operating system. It has a biannual release cycle.
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Q4OS
Q4OS is a Debian-based desktop Linux distribution offering a choice of a classic-style user interface (Trinity) and a modern desktop environment (KDE Plasma). The project also develops various utilities, such as Desktop Profiler and Software Center, as well as installers for third-party applications.