WMApp is a C++ based library for writing WindowMaker-style dockapps. To write
a dockapp, it is generally necessary to perform some magic Xlib incantations,
supply a clipping mask, and set up X event checking. Like larger graphics
libraries such as GTK+ and Qt, WMApp automates this process by providing the
classes and functions necessary for widget creation and callbacks. The library
provides numerous widgets, all with the traditional dockapp appearance. Many
common dockapps could already be rewritten to use this library.

WWW: http://starplot.org/wmapp/