Unfortunatly, even when running on Mac OS X, Free Pascal does not support a behaviour that is compatible to the Apple Human Iterface Guidelines.
In order to cite kamischl's program and company name, the preferences file should have the name "de.schindler.myprogram.plist" in the User's Preferences directory (hence "~/Library/Preferences/de.schindler.myprogram.plist"), but rather, the standard Free pascal routines create a file like "~/.config/myprogram/myprogram.cfg".
Besides the fact that the preferences file has an unexpected name, it is located in an unexpected folder that is usually invisible from the Finder. This behaviour burdens the user unnecessarily.