KWin

KDE’s window manager and compositor: it manages X11 windows in Plasma’s X11 session and runs as a Wayland compositor in Wayland sessions. Window rules, keyboard shortcuts, effects, scripts and workspace behaviour are configurable, and KWin can also be used by desktop shells other than Plasma. KDE announced that Plasma 6.8 will remove the X11 session; X11 applications will continue to run through Xwayland.