diff --git a/COMPILE.txt b/COMPILE.txt
index 15847cc3c..a6d14bad2 100644
--- a/COMPILE.txt
+++ b/COMPILE.txt
@@ -455,7 +455,7 @@ OS X
       probably easier to just install all of them)
     - MacPorts
       - To install the dependencies, run:
-          sudo port install cairo +quartz -x11 pango +quartz -x11 gdk-pixbuf2 -x11 gtk2 +quartz libsigcxx2
+          sudo port install cairo +quartz -x11 pango +quartz -x11 gdk-pixbuf2 -x11 gtk2 +quartz libsigcxx2 gtk-osx-application +no_python
       - gtkmm port will fail to install. Use `-s’ option.
           sudo port -s install gtkmm
       - To install other dependencies and tools.
diff --git a/rtgui/CMakeLists.txt b/rtgui/CMakeLists.txt
index 459c52a9b..9bfbb7e5d 100644
--- a/rtgui/CMakeLists.txt
+++ b/rtgui/CMakeLists.txt
@@ -32,6 +32,11 @@ set (BASESOURCEFILES
 
 include_directories (BEFORE "${CMAKE_CURRENT_BINARY_DIR}")
 
+if (APPLE)
+    # At the time of writing Cmake has no module finder for gtkmacintegration so here we have it hard-coded, if installed via macports it should be in /opt/local/...
+    set (EXTRA_LIB_RTGUI gtkmacintegration)
+    set (EXTRA_INCDIR ${EXTRA_INCDIR} /opt/local/include/gtkmacintegration)
+endif (APPLE)
 if (WIN32)
     set (EXTRA_SRC windirmonitor.cc myicon.rc)
     set (EXTRA_LIB_RTGUI winmm)
@@ -42,9 +47,13 @@ if (WIN32)
     #set_target_properties (rth PROPERTIES LINK_FLAGS "-mwindows")
 else (WIN32)
     include_directories (${EXTRA_INCDIR} ${GLIB2_INCLUDE_DIRS} ${GLIBMM_INCLUDE_DIRS}
-        ${GTK_INCLUDE_DIRS} ${GTKMM_INCLUDE_DIRS} ${GIO_INCLUDE_DIRS} ${GIOMM_INCLUDE_DIRS} ${IPTCDATA_INCLUDE_DIRS} ${LCMS_INCLUDE_DIRS} ${EXPAT_INCLUDE_DIRS} ${FFTW3F_LIBRARY_DIRS} ${GTHREAD_INCLUDE_DIRS} ${GOBJECT_INCLUDE_DIRS} ${CANBERRA-GTK_INCLUDE_DIRS})
+        ${GTK_INCLUDE_DIRS} ${GTKMM_INCLUDE_DIRS} ${GIO_INCLUDE_DIRS} ${GIOMM_INCLUDE_DIRS} ${IPTCDATA_INCLUDE_DIRS}
+        ${LCMS_INCLUDE_DIRS} ${EXPAT_INCLUDE_DIRS} ${FFTW3F_LIBRARY_DIRS} ${GTHREAD_INCLUDE_DIRS} ${GOBJECT_INCLUDE_DIRS}
+        ${CANBERRA-GTK_INCLUDE_DIRS})
     link_directories (${EXTRA_LIBDIR} ${GLIB2_LIBRARY_DIRS} ${GLIBMM_LIBRARY_DIRS}
-        ${GTK_LIBRARY_DIRS} ${GTKMM_LIBRARY_DIRS} ${GIO_LIBRARY_DIRS} ${GIOMM_LIBRARY_DIRS} ${IPTCDATA_LIBRARY_DIRS} ${LCMS_LIBRARY_DIRS} ${EXPAT_LIBRARY_DIRS} ${FFTW3F_LIBRARY_DIRS} ${GTHREAD_LIBRARY_DIRS} ${GOBJECT_LIBRARY_DIRS} ${CANBERRA-GTK_LIBRARY_DIRS})
+        ${GTK_LIBRARY_DIRS} ${GTKMM_LIBRARY_DIRS} ${GIO_LIBRARY_DIRS} ${GIOMM_LIBRARY_DIRS} ${IPTCDATA_LIBRARY_DIRS}
+        ${LCMS_LIBRARY_DIRS} ${EXPAT_LIBRARY_DIRS} ${FFTW3F_LIBRARY_DIRS} ${GTHREAD_LIBRARY_DIRS} ${GOBJECT_LIBRARY_DIRS}
+        ${CANBERRA-GTK_LIBRARY_DIRS})
 endif (WIN32)
 # create config.h which defines where data are stored
 configure_file ("${CMAKE_CURRENT_SOURCE_DIR}/config.h.in" "${CMAKE_CURRENT_BINARY_DIR}/config.h")
@@ -55,6 +64,7 @@ set_target_properties (rth PROPERTIES COMPILE_FLAGS "${CMAKE_CXX_FLAGS}" OUTPUT_
 #target_link_libraries (rth rtengine ${JPEG_LIBRARIES} ${PNG_LIBRARIES} ${ZLIB_LIBRARIES} ${TIFF_LIBRARIES} ${EXTRA_LIB} ${GOBJECT_LIBRARIES} ${GTHREAD_LIBRARIES}
 #   ${GLIB2_LIBRARIES} ${GLIBMM_LIBRARIES} ${GTK_LIBRARIES} ${GTKMM_LIBRARIES} ${GIO_LIBRARIES} ${GIOMM_LIBRARIES} ${LCMS_LIBRARIES} ${IPTCDATA_LIBRARIES})
 target_link_libraries (rth rtengine ${JPEG_LIBRARIES} ${PNG_LIBRARIES} ${ZLIB_LIBRARIES} ${TIFF_LIBRARIES} ${GOBJECT_LIBRARIES} ${GTHREAD_LIBRARIES}
-   ${GLIB2_LIBRARIES} ${GLIBMM_LIBRARIES} ${GTK_LIBRARIES} ${GTKMM_LIBRARIES} ${GIO_LIBRARIES} ${GIOMM_LIBRARIES} ${LCMS_LIBRARIES} ${EXPAT_LIBRARIES} ${FFTW3F_LIBRARIES} ${IPTCDATA_LIBRARIES} ${CANBERRA-GTK_LIBRARIES} ${EXTRA_LIB_RTGUI})
+   ${GLIB2_LIBRARIES} ${GLIBMM_LIBRARIES} ${GTK_LIBRARIES} ${GTKMM_LIBRARIES} ${GIO_LIBRARIES} ${GIOMM_LIBRARIES} ${LCMS_LIBRARIES} ${EXPAT_LIBRARIES}
+   ${FFTW3F_LIBRARIES} ${IPTCDATA_LIBRARIES} ${CANBERRA-GTK_LIBRARIES} ${EXTRA_LIB_RTGUI})
 install (TARGETS rth DESTINATION ${BINDIR})
 
diff --git a/rtgui/rtwindow.cc b/rtgui/rtwindow.cc
index c0ad44429..cf3b31f9a 100644
--- a/rtgui/rtwindow.cc
+++ b/rtgui/rtwindow.cc
@@ -24,6 +24,53 @@
 #include "rtimage.h"
 #include "whitebalance.h"
 
+#if defined(__APPLE__)
+static gboolean
+osx_should_quit_cb (GtkosxApplication *app, gpointer data)
+{
+    RTWindow *rtWin = (RTWindow *)data;
+    return rtWin->on_delete_event(0);
+}
+
+static void
+osx_will_quit_cb (GtkosxApplication *app, gpointer data)
+{
+    RTWindow *rtWin = (RTWindow *)data;
+    rtWin->on_delete_event(0);
+    gtk_main_quit ();
+}
+
+bool RTWindow::osxFileOpenEvent(Glib::ustring path) {
+
+    CacheManager* cm = CacheManager::getInstance();
+    Thumbnail* thm= cm->getEntry( path );
+    if(thm && fpanel){
+        std::vector<Thumbnail*> entries;
+	entries.push_back(thm);
+        fpanel->fileCatalog->openRequested(entries);
+        return true;
+    }
+    return false;
+}
+
+static gboolean
+osx_open_file_cb (GtkosxApplication *app, gchar *path_, gpointer data)
+{
+    RTWindow *rtWin = (RTWindow *)data;
+    if (!argv1.empty()) {
+        // skip handling if we have a file argument or else we get double open of same file
+        return false;
+    }
+    Glib::ustring path = Glib::ustring(path_);
+    Glib::ustring suffix = path.length() > 4 ? path.substr(path.length()-3) : "";
+    suffix = suffix.lowercase();
+    if (suffix == "pp3")  {
+        path = path.substr(0, path.length()-4);
+    }
+    return rtWin->osxFileOpenEvent(path);
+}
+#endif // __APPLE__
+
 RTWindow::RTWindow ()
 :mainNB(NULL)
 ,bpanel(NULL)
@@ -49,6 +96,23 @@ RTWindow::RTWindow ()
 		}
 #endif //GLIBMM_EXCEPTIONS_ENABLED
 
+#if defined(__APPLE__)
+    {
+        osxApp  = (GtkosxApplication *)g_object_new (GTKOSX_TYPE_APPLICATION, NULL);
+        gboolean falseval = FALSE;
+        gboolean trueval = TRUE;
+        RTWindow *rtWin = this;
+        g_signal_connect (osxApp, "NSApplicationBlockTermination", G_CALLBACK (osx_should_quit_cb), rtWin);
+        g_signal_connect (osxApp, "NSApplicationWillTerminate",  G_CALLBACK (osx_will_quit_cb), rtWin);
+        g_signal_connect (osxApp, "NSApplicationOpenFile", G_CALLBACK (osx_open_file_cb), rtWin);
+        // RT don't have a menu, but we must create a dummy one to get the default OS X app menu working
+        GtkWidget *menubar;
+        menubar = gtk_menu_bar_new ();
+        gtkosx_application_set_menu_bar (osxApp, GTK_MENU_SHELL (menubar));
+        gtkosx_application_set_use_quartz_accelerators (osxApp, FALSE);
+        gtkosx_application_ready (osxApp);
+    }
+#endif
     set_title("RawTherapee "+versionString);
     property_allow_shrink() = true;
     set_default_size(options.windowWidth, options.windowHeight);
@@ -58,7 +122,8 @@ RTWindow::RTWindow ()
     	maximize();
     else
     	unmaximize();
-    
+
+    on_delete_has_run = false;
     is_fullscreen = false;
     property_destroy_with_parent().set_value(false);
     signal_window_state_event().connect( sigc::mem_fun(*this, &RTWindow::on_window_state_event) );
@@ -211,6 +276,9 @@ RTWindow::~RTWindow()
     if(!simpleEditor)
         delete pldBridge;
     pldBridge = NULL;
+#if defined(__APPLE__)
+    g_object_unref (osxApp);
+#endif
 }
 
 void RTWindow::findVerNumbers(int* numbers, Glib::ustring versionStr) {
@@ -460,6 +528,11 @@ void RTWindow::addBatchQueueJobs (std::vector<BatchQueueEntry*> &entries) {
 }
 
 bool RTWindow::on_delete_event(GdkEventAny* event) {
+
+    if (on_delete_has_run) {
+        // on Mac OSX we can get multiple events
+        return false;
+    }
     // Check if any editor is still processing, and do NOT quit if so. Otherwise crashes and inconsistent caches
     bool isProcessing=false;
 
@@ -520,7 +593,8 @@ bool RTWindow::on_delete_event(GdkEventAny* event) {
 
     Options::save ();
     hide();
-    return true;
+    on_delete_has_run = true;
+    return false;
 }
 
 void RTWindow::showPreferences () {
diff --git a/rtgui/rtwindow.h b/rtgui/rtwindow.h
index b798613f9..54fbdedca 100644
--- a/rtgui/rtwindow.h
+++ b/rtgui/rtwindow.h
@@ -26,6 +26,9 @@
 #include "progressconnector.h"
 #include "editwindow.h"
 #include "splash.h"
+#if defined(__APPLE__)
+#include <gtkosxapplication.h>
+#endif
 
 class RTWindow : public Gtk::Window, public rtengine::ProgressListener{
 
@@ -39,6 +42,7 @@ class RTWindow : public Gtk::Window, public rtengine::ProgressListener{
         Gtk::ProgressBar prProgBar;
         PLDBridge* pldBridge;
         bool is_fullscreen;
+        bool on_delete_has_run;
         Gtk::Button * btn_fullscreen;
         
         Gtk::Image *iFullscreen, *iFullscreen_exit;
@@ -49,11 +53,17 @@ class RTWindow : public Gtk::Window, public rtengine::ProgressListener{
         bool on_expose_event_epanel(GdkEventExpose* event);
         bool on_expose_event_fpanel(GdkEventExpose* event);
         bool splashClosed(GdkEventAny* event);
+#if defined(__APPLE__)
+        GtkosxApplication *osxApp;
+#endif
 
     public:
         RTWindow ();
         ~RTWindow();
 
+#if defined(__APPLE__)
+        bool osxFileOpenEvent(Glib::ustring path);
+#endif
         void addEditorPanel (EditorPanel* ep,const std::string &name);
         void remEditorPanel (EditorPanel* ep);
         bool selectEditorPanel(const std::string &name);