libxfce4windowing-0-dev - 4.20.0-1 main

This package contains the headers for libxfce4windowing. If you intend to code
wayland applications for the Xfce4 desktop environment, you need to install
this package.
.
The libxfce4windowing Reference Manual is also included and
it can be consulted using Devhelp or a web browser.