diff --git a/docs/reference/gdk/Makefile.am b/docs/reference/gdk/Makefile.am
index c0facc151..43a67508c 100644
--- a/docs/reference/gdk/Makefile.am
+++ b/docs/reference/gdk/Makefile.am
@@ -37,7 +37,7 @@ IGNORE_HFILES=			\
 
 # Extra files to add when scanning (relative to $srcdir)
 EXTRA_HFILES=			\
-	../../../gdk/x11/gdkx.h
+	$(top_srcdir)/gdk/x11/gdkx.h
 
 # CFLAGS and LDFLAGS for compiling scan program. Only needed
 # if $(DOC_MODULE).types is non-empty.
diff --git a/gdk/Makefile.am b/gdk/Makefile.am
index 1b186afa1..f9804aa85 100644
--- a/gdk/Makefile.am
+++ b/gdk/Makefile.am
@@ -2,6 +2,8 @@
 include $(top_srcdir)/Makefile.decl
 -include $(INTROSPECTION_MAKEFILE)
 INTROSPECTION_GIRS =
+INTROSPECTION_SCANNER_ENV = \
+	CC="$(CC)"
 INTROSPECTION_SCANNER_ARGS = \
    --warn-all \
    --add-include-path=../gdk
@@ -213,6 +215,11 @@ Gdk_2_0_gir_CFLAGS = \
 	-I$(top_builddir)	\
 	-I$(top_builddir)/gdk	\
 	$(INCLUDES)
+
+if OS_WIN32
+Gdk_2_0_gir_CFLAGS += -I$(srcdir)/win32 -I$(srcdir)
+endif
+
 INTROSPECTION_GIRS += Gdk-2.0.gir
 
 if USE_X11
@@ -268,6 +275,63 @@ introspection_files += $(filter-out x11/gdkx.h, $(x11_introspection_files))
 
 endif # USE_X11
 
+if OS_WIN32
+win32_introspection_files = \
+	win32/gdkapplaunchcontext-win32.c \
+	win32/gdkcolor-win32.c \
+	win32/gdkcursor-win32.c \
+	win32/gdkdisplay-win32.c \
+	win32/gdkdnd-win32.c \
+	win32/gdkdrawable-win32.c \
+	win32/gdkdrawable-win32.h \
+	win32/gdkevents-win32.c \
+	win32/gdkfont-win32.c \
+	win32/gdkgc-win32.c \
+	win32/gdkgeometry-win32.c \
+	win32/gdkglobals-win32.c \
+	win32/gdkimage-win32.c \
+	win32/gdkim-win32.c \
+	win32/gdkinput.c \
+	win32/gdkinput-win32.c \
+	win32/gdkinput-win32.h \
+	win32/gdkkeys-win32.c \
+	win32/gdkmain-win32.c \
+	win32/gdkpixmap-win32.c \
+	win32/gdkpixmap-win32.h \
+	win32/gdkprivate-win32.h \
+	win32/gdkproperty-win32.c \
+	win32/gdkscreen-win32.c \
+	win32/gdkselection-win32.c \
+	win32/gdkspawn-win32.c \
+	win32/gdktestutils-win32.c \
+	win32/gdkvisual-win32.c \
+	win32/gdkwin32.h \
+	win32/gdkwin32id.c \
+	win32/gdkwin32keys.h \
+	win32/gdkwindow-win32.c \
+	win32/gdkwindow-win32.h
+
+GdkWin32-2.0.gir: $(gdktargetlib) Gdk-2.0.gir Makefile
+GdkWin32_2_0_gir_SCANNERFLAGS = --warn-all --identifier-prefix=Gdk --symbol-prefix=gdk --include-uninstalled=Gdk-2.0.gir
+GdkWin32_2_0_gir_INCLUDES = Gio-2.0 Gdk-2.0 GdkPixbuf-2.0 Pango-1.0
+GdkWin32_2_0_gir_LIBS = $(gdktargetlib)
+GdkWin32_2_0_gir_FILES = $(win32_introspection_files)
+GdkWin32_2_0_gir_EXPORT_PACKAGES = gdk-win32-2.0
+GdkWin32_2_0_gir_CFLAGS = \
+	-DGDK_COMPILATION \
+	-I$(top_srcdir) \
+	-I$(top_builddir) \
+	-I$(top_builddir)/gdk \
+	-I$(srcdir)/win32 \
+	-I$(srcdir) \
+	$(INCLUDES) \
+	-L$(top_builddir)/gdk
+INTROSPECTION_GIRS += GdkWin32-2.0.gir
+
+introspection_files += $(filter-out win32/gdkwin32.h, $(win32_introspection_files))
+
+endif # OS_WIN32
+
 girdir = $(datadir)/gir-1.0
 gir_DATA = $(INTROSPECTION_GIRS)
 
diff --git a/gdk/makegdkalias.pl b/gdk/makegdkalias.pl
index 97a6e6007..27646cc0a 100755
--- a/gdk/makegdkalias.pl
+++ b/gdk/makegdkalias.pl
@@ -14,7 +14,7 @@ print <<EOF;
 
 #include <glib.h>
 
-#ifdef G_HAVE_GNUC_VISIBILITY
+#if defined(G_HAVE_GNUC_VISIBILITY) && !defined(__APPLE__)
 
 EOF
 
diff --git a/gdk/quartz/GdkQuartzView.c b/gdk/quartz/GdkQuartzView.c
index 368e040ec..bad737da2 100644
--- a/gdk/quartz/GdkQuartzView.c
+++ b/gdk/quartz/GdkQuartzView.c
@@ -599,6 +599,25 @@
     gdk_screen_get_rgba_colormap (_gdk_screen);
 }
 
+-(void)viewWillDraw
+{
+  /* macOS 11 (Big Sur) and newer may use a higher precision backing
+   * format for layer contents.  For GTK2's 8-bit drawing this can add
+   * avoidable conversion overhead.  Use a dynamic Objective-C call here
+   * instead of a hard QuartzCore/CALayer dependency, so old SDKs and old
+   * macOS targets keep building and keep their old behaviour.
+   */
+  if (gdk_quartz_osx_version () >= GDK_OSX_BIG_SUR)
+    {
+      id layer = [self layer];
+
+      if (layer && [layer respondsToSelector: @selector(setContentsFormat:)])
+        [layer setValue: @"RGBA8Uint" forKey: @"contentsFormat"];
+    }
+
+  [super viewWillDraw];
+}
+
 -(void)drawRect: (NSRect)rect
 {
   GdkRectangle gdk_rect;
diff --git a/gdk/quartz/gdkdrawable-quartz.c b/gdk/quartz/gdkdrawable-quartz.c
index 11dd12737..eb520f08d 100644
--- a/gdk/quartz/gdkdrawable-quartz.c
+++ b/gdk/quartz/gdkdrawable-quartz.c
@@ -893,7 +893,8 @@ gdk_quartz_drawable_release_context (GdkDrawable  *drawable,
       if (window_impl->in_paint_rect_count == 0)
         {
           _gdk_quartz_drawable_flush (drawable);
-          [window_impl->view unlockFocus];
+          if (gdk_quartz_osx_version () < GDK_OSX_MOJAVE)
+            [window_impl->view unlockFocus];
         }
     }
   else if (GDK_IS_PIXMAP_IMPL_QUARTZ (drawable))
diff --git a/gdk/quartz/gdkglobals-quartz.c b/gdk/quartz/gdkglobals-quartz.c
index f013f2830..4e596eef5 100644
--- a/gdk/quartz/gdkglobals-quartz.c
+++ b/gdk/quartz/gdkglobals-quartz.c
@@ -34,9 +34,20 @@ gdk_quartz_osx_version (void)
 
   if (minor == GDK_OSX_UNSUPPORTED)
     {
-      OSErr err = Gestalt (gestaltSystemVersionMinor, (SInt32*)&minor);
+      gint32 major = GDK_OSX_UNSUPPORTED;
+      OSErr err = Gestalt (gestaltSystemVersionMajor, (SInt32*)&major);
 
       g_return_val_if_fail (err == noErr, GDK_OSX_UNSUPPORTED);
+
+      err = Gestalt (gestaltSystemVersionMinor, (SInt32*)&minor);
+      g_return_val_if_fail (err == noErr, GDK_OSX_UNSUPPORTED);
+
+      /* GTK2 encodes macOS 10.x releases by their minor version.
+       * Map macOS 11+ into the same sequence:
+       * 11 -> 16, 12 -> 17, 13 -> 18, ...
+       */
+      if (major > 10)
+        minor = major + 5;
     }
 
   if (minor < GDK_OSX_MIN)
diff --git a/gdk/quartz/gdkquartz.h b/gdk/quartz/gdkquartz.h
index 8206db019..42aac50b9 100644
--- a/gdk/quartz/gdkquartz.h
+++ b/gdk/quartz/gdkquartz.h
@@ -54,7 +54,13 @@ typedef enum
   GDK_OSX_SIERRA = 12,
   GDK_OSX_HIGH_SIERRA = 13,
   GDK_OSX_MOJAVE = 14,
-  GDK_OSX_CURRENT = 14,
+  GDK_OSX_CATALINA = 15,
+  GDK_OSX_BIG_SUR = 16,
+  GDK_OSX_MONTEREY = 17,
+  GDK_OSX_VENTURA = 18,
+  GDK_OSX_SONOMA = 19,
+  GDK_OSX_SEQUOIA = 20,
+  GDK_OSX_CURRENT = 20,
   GDK_OSX_NEW = 99
 } GdkOSXVersion;
 
diff --git a/gdk/quartz/gdkwindow-quartz.c b/gdk/quartz/gdkwindow-quartz.c
index 6c7a2facb..38ada80b2 100644
--- a/gdk/quartz/gdkwindow-quartz.c
+++ b/gdk/quartz/gdkwindow-quartz.c
@@ -104,7 +104,8 @@ gdk_window_impl_quartz_get_context (GdkDrawable *drawable,
    * and for widgets that send fake expose events like the arrow
    * buttons in spinbuttons or the position marker in rulers.
    */
-  if (window_impl->in_paint_rect_count == 0)
+  if (window_impl->in_paint_rect_count == 0 &&
+      gdk_quartz_osx_version () < GDK_OSX_MOJAVE)
     {
       if (![window_impl->view lockFocusIfCanDraw])
         return NULL;
@@ -468,7 +469,8 @@ _gdk_windowing_before_process_all_updates (void)
 {
   in_process_all_updates = TRUE;
 
-  NSDisableScreenUpdates ();
+  if (gdk_quartz_osx_version () < GDK_OSX_MOJAVE)
+    NSDisableScreenUpdates ();
 }
 
 void
@@ -489,8 +491,9 @@ _gdk_windowing_after_process_all_updates (void)
 
       /* 10.14 needs to be told that the view needs to be redrawn, see
        * https://gitlab.gnome.org/GNOME/gtk/issues/1479 */
-      if (gdk_quartz_osx_version() >= GDK_OSX_MOJAVE)
-           [[nswindow contentView] setNeedsDisplay:YES];
+      if (gdk_quartz_osx_version () >= GDK_OSX_MOJAVE &&
+          gdk_quartz_osx_version () < GDK_OSX_BIG_SUR)
+        [[nswindow contentView] setNeedsDisplay:YES];
       [nswindow enableFlushWindow];
       [nswindow flushWindow];
       [nswindow release];
@@ -502,7 +505,8 @@ _gdk_windowing_after_process_all_updates (void)
 
   in_process_all_updates = FALSE;
 
-  NSEnableScreenUpdates ();
+  if (gdk_quartz_osx_version () < GDK_OSX_MOJAVE)
+    NSEnableScreenUpdates ();
 }
 
 static void
diff --git a/gdk/win32/gdkkeys-win32.c b/gdk/win32/gdkkeys-win32.c
index d8ab30347..9a34083c4 100644
--- a/gdk/win32/gdkkeys-win32.c
+++ b/gdk/win32/gdkkeys-win32.c
@@ -692,6 +692,7 @@ update_keymap (GdkKeymap *gdk_keymap)
   if (hkls_len != keymap->layout_handles->len)
     keymap->keysym_tab = g_renew (guint, keymap->keysym_tab, keysym_tab_size);
 
+  memset (key_state, 0, sizeof(key_state));
   memset (keymap->keysym_tab, 0, keysym_tab_size);
   g_array_set_size (keymap->layout_handles, hkls_len);
   g_array_set_size (keymap->options, hkls_len);
diff --git a/gdk/win32/gdkwindow-win32.c b/gdk/win32/gdkwindow-win32.c
index b7ea0404a..1a21a1b67 100644
--- a/gdk/win32/gdkwindow-win32.c
+++ b/gdk/win32/gdkwindow-win32.c
@@ -2767,6 +2767,10 @@ _gdk_windowing_window_at_pointer (GdkDisplay *display,
        * WindowFromPoint() can find our windows, we follow similar logic
        * here, and ignore invisible and disabled windows.
        */
+      UINT cwp_flags = CWP_SKIPDISABLED  |
+                       CWP_SKIPINVISIBLE |
+                       CWP_SKIPTRANSPARENT;
+
       hwnd = GetDesktopWindow ();
       do {
         window = gdk_win32_handle_table_lookup ((GdkNativeWindow) hwnd);
@@ -2777,8 +2781,7 @@ _gdk_windowing_window_at_pointer (GdkDisplay *display,
           break;
 
         screen_to_client (hwnd, screen_pt, &client_pt);
-        hwndc = ChildWindowFromPointEx (hwnd, client_pt, CWP_SKIPDISABLED  |
-                                                         CWP_SKIPINVISIBLE);
+        hwndc = ChildWindowFromPointEx (hwnd, client_pt, cwp_flags);
 
 	/* Verify that we're really inside the client area of the window */
 	if (hwndc != hwnd)
@@ -2789,6 +2792,8 @@ _gdk_windowing_window_at_pointer (GdkDisplay *display,
 	      hwndc = hwnd;
 	  }
 
+        /* Only ignore top-level transparent windows */
+        cwp_flags &= ~CWP_SKIPTRANSPARENT;
       } while (hwndc != hwnd && (hwnd = hwndc, 1));
 
     }
diff --git a/gtk/Makefile.am b/gtk/Makefile.am
index 5cbe2a326..083fd07b7 100644
--- a/gtk/Makefile.am
+++ b/gtk/Makefile.am
@@ -2,6 +2,9 @@
 include $(top_srcdir)/Makefile.decl
 -include $(INTROSPECTION_MAKEFILE)
 INTROSPECTION_GIRS =
+INTROSPECTION_SCANNER_ENV = \
+	CC="$(CC)" \
+	PATH="$(builddir):$(builddir)/.libs:$${PATH}:"
 INTROSPECTION_SCANNER_ARGS = \
 	--warn-all \
 	--add-include-path=../gdk
@@ -1139,7 +1142,7 @@ $(GTK_UPDATE_ICON_CACHE_MANIFEST):
 	 echo '</assembly>' ) >$@
 
 $(GTK_UPDATE_ICON_CACHE_RC):
-	(echo -e '#include <winbase.h>\nCREATEPROCESS_MANIFEST_RESOURCE_ID RT_MANIFEST '$(GTK_UPDATE_ICON_CACHE_MANIFEST)) >$@
+	(echo -e '#include <winbase.h>\nCREATEPROCESS_MANIFEST_RESOURCE_ID RT_MANIFEST "'$(GTK_UPDATE_ICON_CACHE_MANIFEST)'"') >$@
 
 $(GTK_UPDATE_ICON_CACHE_MANIFEST_OBJECT): $(GTK_UPDATE_ICON_CACHE_RC) $(GTK_UPDATE_ICON_CACHE_MANIFEST)
 	$(WINDRES) --input $< --output $@ --output-format=coff
diff --git a/gtk/gtkcalendar.c b/gtk/gtkcalendar.c
index 19dc0196f..2e453db04 100644
--- a/gtk/gtkcalendar.c
+++ b/gtk/gtkcalendar.c
@@ -710,7 +710,7 @@ gtk_calendar_init (GtkCalendar *calendar)
     for (i=0; i<7; i++)
       {
 #ifndef G_OS_WIN32
-        tmp_dt = g_date_time_new_utc (2001, 1, i + 1, 12, 0, 0.0);
+        tmp_dt = g_date_time_new_utc (2001, 1, i + 7, 12, 0, 0.0);
         if (tmp_dt)
           {
             tmp_str = g_date_time_format (tmp_dt, "%a");
diff --git a/gtk/gtkcontainer.c b/gtk/gtkcontainer.c
index 2f7007fd2..e4c98c8c2 100644
--- a/gtk/gtkcontainer.c
+++ b/gtk/gtkcontainer.c
@@ -40,6 +40,9 @@
 #include "gtktoolbar.h"
 #include <gobject/gobjectnotifyqueue.c>
 #include <gobject/gvaluecollector.h>
+#ifdef GDK_WINDOWING_QUARTZ
+#include "gdk/quartz/gdkquartz.h"
+#endif
 #include "gtkalias.h"
 
 
@@ -1357,7 +1360,16 @@ gtk_container_idle_sizer (gpointer data)
       gtk_container_check_resize (GTK_CONTAINER (widget));
     }
 
+#ifdef GDK_WINDOWING_QUARTZ
+  /* macOS 11 and newer can trigger expensive full-window redraws here.
+   * Keep the traditional update processing path for older Quartz targets,
+   * but let the normal GDK update idle handle updates on Big Sur and newer.
+   */
+  if (gdk_quartz_osx_version () < GDK_OSX_BIG_SUR)
+    gdk_window_process_all_updates ();
+#else
   gdk_window_process_all_updates ();
+#endif
 
   return FALSE;
 }
diff --git a/gtk/gtkicontheme.c b/gtk/gtkicontheme.c
index 0d4435c72..f8aaf9a3b 100644
--- a/gtk/gtkicontheme.c
+++ b/gtk/gtkicontheme.c
@@ -2945,6 +2945,10 @@ icon_info_ensure_scale_and_pixbuf (GtkIconInfo  *icon_info,
 
               if (mime_type && strcmp (mime_type, "image/svg+xml") == 0)
                 is_svg = TRUE;
+#ifdef G_OS_WIN32
+              else if (content_type && strcmp (content_type, ".svg") == 0)
+                is_svg = TRUE;
+#endif
             }
 
           g_object_unref (file_info);
diff --git a/gtk/gtkquartz.c b/gtk/gtkquartz.c
index 87ba87745..caf8404f8 100644
--- a/gtk/gtkquartz.c
+++ b/gtk/gtkquartz.c
@@ -67,7 +67,10 @@ _gtk_quartz_create_image_from_pixbuf (GdkPixbuf *pixbuf)
     }
   [nsimage lockFocus];
 
-  context = (CGContextRef)[[NSGraphicsContext currentContext] graphicsPort];
+  if (gdk_quartz_osx_version () < GDK_OSX_YOSEMITE)
+    context = (CGContextRef)[[NSGraphicsContext currentContext] graphicsPort];
+  else
+    context = [[NSGraphicsContext currentContext] CGContext];
   CGContextDrawImage (context, CGRectMake (0, 0, pixbuf_width, pixbuf_height), image);
 
   [nsimage unlockFocus];
diff --git a/gtk/gtkrc.c b/gtk/gtkrc.c
index 7bfbea85c..d316a0d90 100644
--- a/gtk/gtkrc.c
+++ b/gtk/gtkrc.c
@@ -808,6 +808,8 @@ gtk_rc_parse_named (GtkRcContext *context,
   gchar *path = NULL;
   const gchar *home_dir;
   gchar *subpath;
+  const gchar * const *xdg_data_dirs;
+  gint i;
 
   if (type)
     subpath = g_strconcat ("gtk-2.0-", type,
@@ -829,6 +831,22 @@ gtk_rc_parse_named (GtkRcContext *context,
 	}
     }
 
+  if (!path)
+    {
+      xdg_data_dirs = g_get_system_data_dirs ();
+      for (i = 0; xdg_data_dirs[i]; i++)
+        {
+          path = g_build_filename (xdg_data_dirs[i], "themes", name, subpath, NULL);
+          if (g_file_test (path, G_FILE_TEST_EXISTS))
+            break;
+          else
+            {
+              g_free (path);
+              path = NULL;
+            }
+        }
+    }
+
   if (!path)
     {
       gchar *theme_dir = gtk_rc_get_theme_dir ();
diff --git a/gtk/makegtkalias.pl b/gtk/makegtkalias.pl
index 3f956b05e..67ec7c973 100755
--- a/gtk/makegtkalias.pl
+++ b/gtk/makegtkalias.pl
@@ -14,7 +14,7 @@ print <<EOF;
 
 #include <glib.h>
 
-#ifdef G_HAVE_GNUC_VISIBILITY
+#if defined(G_HAVE_GNUC_VISIBILITY) && !defined(__APPLE__)
 
 EOF
 
diff --git a/gtk/tests/builder.c b/gtk/tests/builder.c
index ebba220e9..121012704 100644
--- a/gtk/tests/builder.c
+++ b/gtk/tests/builder.c
@@ -132,7 +132,7 @@ static int object = 0;
 static int object_after = 0;
 
 void /* exported for GtkBuilder */
-signal_normal (GtkWindow *window, GParamSpec spec)
+signal_normal (GtkWindow *window, GParamSpec *spec)
 {
   g_assert (GTK_IS_WINDOW (window));
   g_assert (normal == 0);
@@ -142,7 +142,7 @@ signal_normal (GtkWindow *window, GParamSpec spec)
 }
 
 void /* exported for GtkBuilder */
-signal_after (GtkWindow *window, GParamSpec spec)
+signal_after (GtkWindow *window, GParamSpec *spec)
 {
   g_assert (GTK_IS_WINDOW (window));
   g_assert (normal == 1);
@@ -152,7 +152,7 @@ signal_after (GtkWindow *window, GParamSpec spec)
 }
 
 void /* exported for GtkBuilder */
-signal_object (GtkButton *button, GParamSpec spec)
+signal_object (GtkButton *button, GParamSpec *spec)
 {
   g_assert (GTK_IS_BUTTON (button));
   g_assert (object == 0);
@@ -162,7 +162,7 @@ signal_object (GtkButton *button, GParamSpec spec)
 }
 
 void /* exported for GtkBuilder */
-signal_object_after (GtkButton *button, GParamSpec spec)
+signal_object_after (GtkButton *button, GParamSpec *spec)
 {
   g_assert (GTK_IS_BUTTON (button));
   g_assert (object == 1);
@@ -172,28 +172,28 @@ signal_object_after (GtkButton *button, GParamSpec spec)
 }
 
 void /* exported for GtkBuilder */
-signal_first (GtkButton *button, GParamSpec spec)
+signal_first (GtkButton *button, GParamSpec *spec)
 {
   g_assert (normal == 0);
   normal = 10;
 }
 
 void /* exported for GtkBuilder */
-signal_second (GtkButton *button, GParamSpec spec)
+signal_second (GtkButton *button, GParamSpec *spec)
 {
   g_assert (normal == 10);
   normal = 20;
 }
 
 void /* exported for GtkBuilder */
-signal_extra (GtkButton *button, GParamSpec spec)
+signal_extra (GtkButton *button, GParamSpec *spec)
 {
   g_assert (normal == 20);
   normal = 30;
 }
 
 void /* exported for GtkBuilder */
-signal_extra2 (GtkButton *button, GParamSpec spec)
+signal_extra2 (GtkButton *button, GParamSpec *spec)
 {
   g_assert (normal == 30);
   normal = 40;