14.2.2 Setting and Reading the WM_CLIENT_MACHINE Property
Xlib provides functions that you can use to set and read
the WM_CLIENT_MACHINE property for a given window.
To set a window's WM_CLIENT_MACHINE property, use
XSetWMClientMachine().
To read a window's WM_CLIENT_MACHINE property, use
XGetWMClientMachine().
Christophe Tronche, ch@tronche.com