Q4OS is a Linux distribution built on Debian, designed for users transitioning from Windows. It features the KDE Plasma desktop environment, known for its balance of elegance and user-friendliness, and also supports the Trinity desktop environment. The Welcome app includes a Desktop Profiler tool for switching between different Q4OS versions and installing alternative desktop environments. Q4OS comes preinstalled with applications like LibreOffice, Chromium, Thunderbird, and VLC, and utilizes the Flatpak package manager for additional software. Users can access apps through KDE Discover and the Q4OS Software Center, which includes tools like LookSwitcher for changing KDE Plasma themes. Q4OS prioritizes stability by following the Debian development model, ensuring a reliable operating system. It is available for free download, and the q4os-winsetup tool allows Windows users to set up a dual-boot system.