xdpyinfo	X windows info
/etc/X11/gdm/Sessions/Default	default setup
=================================================
zaph.com/Modeline	calculate XFree86 Modelines
john.snoop.dk//programs/linux/read-edid/read-edid.tar.gz
=================================================
import -display :0 -window root snap1.png
$ xauth add navel/unix:0 MIT-MAGIC-COOKIE-1
1b3a196c7073742666264b1b0e111f77
    $ xauth add localhost:0 MIT-MAGIC-COOKIE-1 1b3a196c7073742666264b1b0e111f77

...and give the snapshot another try:

    $ import -display :0 -window root /tmp/wdm.png
=================================================
xauth add :0 XDM-AUTHORIZATION-1
        [put a whole lot of hex characters here... an even number of them]
	xauth extract - :0 | ssh -l
	        otherhat@localhost xauth merge -
		keep ssh alive
================================================= /usr//lib/X11/XKeysymDB
xmodmap
===================================== X-windows
cal | xmessage -file - -title "Calendar"
ctrl-alt-f2
startx -- :1
'startx' automatically runs 'startx -- :0'
switch back to your first X sessions by doing a
crtl-alt-F7 and back again to your second by ctrl-alt-F8
startx -- -cc StaticGrey
 
- Running X on a specific VC:
   
startx -- :0 vt7 &      # Launches display 0 to VC7 (standard)
startx -- :2 vt22 &     # Launches display 2 to VC22 (nonstd)

To get to a specific VC, use the 'chvt' command with the appropriate arg
=================================================
X doesn't use inetd at all.  It just listens for connections on port 6000,
normally.  You could block traffic to that port with IP firewalling, or on
an external router.  Or you could just use stronger authentication within
the X server.  Unless you're using XDM to run logins, you can just do that
with by putting an .xserverrc file in your home directory:
 
    exec /usr/X11R6/bin/XF86_Mach64 -auth $HOME/.Xauthority -bpp 16

        xrdb -merge $HOME/.Xdefaults
        xterm....whatever
        ...other xterm apps...
        fvwm95-2 &
        xscreensaver -cycle 1 -timeout 5 -lock -lock-timeout 15  &
        exec `color_xterm -C -title CONSOLE -name console -geometry 160x25+0+5 
-bg DarkBlue -fg Gold -font 6x10`

=================================================
Getting Xauthority properly setup is not difficult.  The general picture
of what's going on is:

  1) Some program generates a magic cookie (arbitrary string) and writes
  this to a file.

  2) The name of this file (often ~/.Xauthority) is passed to the X
  server.
  3) The X server writes an entry for the DISPLAY into your
  ~/.Xauthority file.

  4) Xlib reads ~/.Xauthority when you create a window, and passes the
  cookie value back to the X server.

See your X11 init and control scripts (usually down under /etc/X11) for
details.  This is no hard stuff.  To (re)synchronise the session key
across hosts:

  xauth nlist $DISPLAY | rsh other.host xauth nmerge -

Or just use SSH's X11 forwarding.