diff --git a/FL/mac.H b/FL/mac.H
index eba5c9497..e33dc4c16 100644
--- a/FL/mac.H
+++ b/FL/mac.H
@@ -281,6 +281,14 @@ extern void fl_mac_set_about( Fl_Callback *cb, void *user_data, int shortcut = 0
  */
 extern int fl_mac_os_version;
 
+/** Determines whether cmd-Q or the "Quit xxx" item of application menu terminates the app or only the event loop.
+ By default, fl_mac_quit_early = 1, and cmd-Q or "Quit xxx" terminate the app when all windows are closed
+ without Fl::run() returning. If fl_mac_quit_early is set to 0, cmd-Q or "Quit xxx" terminate only the event loop
+ when all windows are closed, and Fl::run() returns.
+ \note This OS-specific variable will not be part of the API of FLTK 1.4.
+ */
+extern int fl_mac_quit_early;
+
 /** The system menu bar.
  */
 extern class Fl_Sys_Menu_Bar *fl_sys_menu_bar;
diff --git a/documentation/src/osissues.dox b/documentation/src/osissues.dox
index 829c3d5e7..baa00f112 100644
--- a/documentation/src/osissues.dox
+++ b/documentation/src/osissues.dox
@@ -732,9 +732,20 @@ Apple "Quit" Event
 
 \par
 When the user presses Cmd-Q or requests a termination of the
-application, OS X will send a "Quit" Apple Event. FLTK handles
-this event by sending an \c FL_CLOSE event to all open
-windows. If all windows close, the application will terminate.
+application, FLTK reacts sending an \c FL_CLOSE event to all open
+windows. If any window remains open, the termination request aborts,
+and the app continues. If all windows close, FLTK default behaviour
+is to terminate the application immediately, without letting Fl::run()
+return. Consequently, potential cleanup code placed after the Fl::run()
+call does not run, and potential global destructors that would run
+after main() would return do not run. All code that should run so
+the app cleanly terminates must therefore be placed in
+window callbacks (which run when windows are closed) or in atexit()
+functions.
+Alternatively, FLTK can be directed to just terminate the event loop
+and therefore let potential cleanup code placed after return from Fl::run()
+and from main() execute. This is obtained setting global variable
+\ref fl_mac_quit_early to 0.
 
 Apple "Open" Event
 
diff --git a/src/Fl_cocoa.mm b/src/Fl_cocoa.mm
index c8be6c0c6..2e3244980 100644
--- a/src/Fl_cocoa.mm
+++ b/src/Fl_cocoa.mm
@@ -81,6 +81,7 @@ static unsigned make_current_counts = 0; // if > 0, then Fl_Window::make_current
 static NSBitmapImageRep* rect_to_NSBitmapImageRep(Fl_Window *win, int x, int y, int w, int h);
 
 int fl_mac_os_version = Fl_X::calc_mac_os_version();		// the version number of the running Mac OS X (e.g., 100604 for 10.6.4)
+int fl_mac_quit_early = 1; // set it to 0 so cmd-Q does not terminate app but merely terminates the event loop
 
 // public variables
 CGContextRef fl_gc = 0;
@@ -1533,7 +1534,7 @@ static FLWindowDelegate *flwindowdelegate_instance = nil;
 - (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication*)sender
 {
   fl_lock_function();
-  NSApplicationTerminateReply reply = NSTerminateNow;
+  NSApplicationTerminateReply reply = (fl_mac_quit_early ? NSTerminateNow : NSTerminateCancel);
   while ( Fl_X::first ) {
     Fl_Window *win = Fl::first_window();
     if (win->parent()) win = win->top_window();