// this code creates a top level window, and draws whatever is in the nib file
// if there is no nib file, the app will draw nothing and no top window appears
// Xcode template puts this code into three files, but they can be merged into one .m file:

#import <Cocoa/Cocoa.h>
int main(int argc, char *argv[])
{
    return NSApplicationMain(argc,  (const char **) argv);
}

@interface cocoa_test2AppDelegate : NSObject <NSApplicationDelegate> {
    NSWindow *window;
}
@property (assign) IBOutlet NSWindow *window;
@end

@implementation cocoa_test2AppDelegate
@synthesize window;
// The @synthesize directive automatically generates the setters and getters 
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
	// Insert code here to initialize your application 
}
@end

and this file must exist:
  cocoa_test2_bundle.app/Contents/Resources/English.lproj/MainMenu.nib