xdmchooser is a modified version of the standard X11 chooser, with
a slightly nicer 3D-ish interface.  Instead of broadcasting, it
allows the user to supply a host via the keyboard.  This is useful
when the list of machines extends beyond the limit of a broadcast,
or is too cumbersome to enter on the command line (in one of the
xdm config files).

xdmping is a quick way of determining if a host is willing to provide
an xdm login session.  This is probably only useful in certain
circumstances.

To get this to work, add/modify the following line in the xdm-config
file:

DisplayManager*chooser:         ${PREFIX}/bin/xdmchooser