Accessing Other AppsDefaults

Well, it does...just not in a nice, neat format yet (see below). You can take your pick without worrying, though; Apple says that you can even mix CFPreferences and NSUserDefaults without harm. Also, you don't have to include the whole Carbon framework for this, just CoreFoundation (which may even already be included in the Cocoa framework).

NSDictionary *safariPrefs = [[NSUserDefaults standardUserDefaults] persistentDomainForName:@"com.apple.Safari"];
BOOL tabbedBrowsingEnabled  = [safariPrefs objectForKey:@"TabbedBrowsing"];
// ...
// If you want to set something, you have to do it like this, unfortunately,
// instead of modifying a specific value
[[NSUserDefaults standardUserDefaults] setPersistentDomain:safariPrefs forName:@"com.apple.Safari"];

浏览方法
NSString *s;
NSEnumerator *e = [myDict keyEnumerator];
while (s = [e nextObject]) {
NSLog(@"key is %@, value is %@", s, [myDict objectForKey:s]);
}