This lets you enable the floating/transparent board in Apple's Chess application without modifying the app at all. I originally posted this to Slashdot here. After taking a look at the source, I found out that the floating window can be activated without making any modifications to the application. Here's how to enable the transparent window. Open Terminal.app and set MBC_DEBUG as an environment variable to 16. With bash:
set MBC_DEBUG=16
With tcsh:
setenv MBC_DEBUG 16
Now, open Chess.app from the Terminal:
open /Applications/Chess.app/
There will be a new menu item (Floating Board) under the "Game" menu. Selecting this menu item will toggle the floating board on and off. There seems to be a bug with the mouse behavior (I can't move any pieces), and I assume this is why this feature was removed. I found that you can get around this bug by doing the following:
Mac OS X Hints
http://hints.macworld.com/article.php?story=20040330160753686