Disable the 10.5 X11 Warning-on-quit Dialog

One of the less-widely-used programs included with OS X, as an optional install, is X11, Apple's implementation of the X Window System. Using X11, you can run programs that haven't been ported to run natively on OS X--programs like GIMP, a free alternative to image editors such as Photoshop. Without X11, you can't run GIMP. (The easiest way to use GIMP on OS X is to use an installer, such as those available on Wilber loves Apple. Each package has an installation help page as well (ie 10.5.2) to guide you through the process.)

If you'd like to know more about X11, you can read a somewhat-technical but useful introduction to X11 in this document on Apple's developer site.)

If you run GIMP or other X11 programs, they'll launch X11 for you automatically in the background. When you quit those programs, however, they don't automatically quit X11. When you do go to quit X11 yourself, you'll be greeted (in OS X 10.5) with a confirmation dialog, asking if this is really what you want to do. After answering yes the first half-dozen times, this gets really old. Thankfully, there's a simple Terminal solution. Quit X11, open Terminal (in Applications -> Utilities), and enter this command:

After that, X11 will no longer pester you when send it a Command-Q, or for you menu lovers, select File -> Quit X11. If you'd like the old behavior back, just repeat the above command (when X11 isn't running), but replace true with false.