Packages with the xcomposite use flag

Global definition: Enable support for the Xorg composite extension.

app-emulation / wine-staging : Free implementation of Windows(tm) on Unix, with Wine-Staging patchset

app-emulation / wine-vanilla : Free implementation of Windows(tm) on Unix, without external patchsets

x11-misc / x11vnc : VNC server for real X displays

x11-wm / e16 : Enlightenment Window Manager (E16)

xfce-base / xfwm4 : Window manager for the Xfce desktop environment