Suppressing xterm when XQuartz starts up.

Since XQuartz version 2.6.1, as I recall, XQuartz started to execute xterm if it is executed from dock or is launched automatically when you log on to the system (by your setup). It is quite like a pain in your butt if you made XQuartz run when you log on to your OS X. Here's how to keep XQuartz from running xterm when it is starting up: type following command in your terminal:

defaults write org.macosforge.xquartz.X11 app_to_run /usr/bin/true

More about this subject, refer to this page: http://xquartz.macosforge.org/trac/wiki/X11-UsersFAQ

P.S. Actually, older versions of XQuartz also did the same thing -- ran xterm when being started up by specific user action, e.g. clicking on the XQuartz icon on the dock or run a command like 'open XQuartz' or adding XQuartz to your logon items. It was just easy to tell XQuartz to stop launching xterm. You did not even need to run defaults command.