A window manager is required in order to decorate, move, resize, and perform other operations on individual X windows.
Cygwin/X can work with window managers in several different ways:
Internal window manager for multiwindow mode. The internal window
manager that creates a Windows window for each top-level X window
is automatically started when using the
command-line parameter to X. See the Section called Command line parameters in Chapter 3 for more information
External local window managers (e.g. twm, mwm (part of the lesstif package), fvwm2, openbox, aewm++, WindowMaker). These local window managers must be installed on Cygwin and run locally.
Remote window managers started by logging into an XDMCP session. You can read more about XDMCP in the Section called Remote sessions via XDMCP.
Remote window manager launched through an ssh tunnel. This is not Cygwin/X-specific, so you should be able to find information about launching remote window managers from other sources. See the Section called Secure ssh for more information on using ssh.