KWin

KWin is the window manager and compositor used by the KDE Plasma desktop environment. It is responsible for placing and decorating windows, handling user input, and rendering the desktop scene. In X11 sessions, KWin acts as the window manager, while in Wayland sessions it serves as the compositor and window manager for Wayland clients, coordinating rendering and input for the session.

KWin integrates with KDE technologies and Plasma features such as multiple desktops, activities, and window rules. It includes a range of visual effects and window decorations, supports transparency and shadows, and provides animation during window movements and transitions. The compositor can manage hardware-accelerated rendering and provides options for performance and quality. Users can extend or customize behavior through KWin Scripts, and can adjust window management policies, keyboard shortcuts, and focus models.

As a modern compositor, KWin supports both X11 and Wayland backends. It uses OpenGL-based compositing by default, with fallbacks to other rendering methods when needed. In Wayland sessions, KWin functions as the primary Wayland compositor for the user’s session, coordinating the rendering of surfaces and the interaction between clients and input devices. KWin also offers optional tiling functionality through community scripts, enabling tiling-like layouts without changing the core window management model.

KWin is developed by the KDE community and shipped as part of the KDE Plasma desktop. It is commonly included in KDE-focused Linux distributions and remains central to the user experience of Plasma.