diff --git a/WINGs/WINGs/WINGs.h b/WINGs/WINGs/WINGs.h
index 47981744..5235c20f 100644
--- a/WINGs/WINGs/WINGs.h
+++ b/WINGs/WINGs/WINGs.h
@@ -26,7 +26,7 @@
 #include <WINGs/WUtil.h>
 #include <X11/Xlib.h>
 
-#define WINGS_H_VERSION  20141205
+#define WINGS_H_VERSION  20150508
 
 
 #ifdef __cplusplus
@@ -127,7 +127,8 @@ typedef enum {
     WBTRadio = 5,
     WBTMomentaryChange = 6,
     WBTOnOff = 7,
-    WBTMomentaryLight = 8
+    WBTMomentaryLight = 8,
+    WBTTriState = 9
 } WMButtonType;
 
 /* button behaviour masks */
diff --git a/WINGs/WINGs/WINGsP.h b/WINGs/WINGs/WINGsP.h
index fc18b1cb..4cbe0fc2 100644
--- a/WINGs/WINGs/WINGsP.h
+++ b/WINGs/WINGs/WINGsP.h
@@ -268,6 +268,16 @@ typedef struct W_Screen {
     struct W_View *modalView;
     unsigned modalLoop:1;
     unsigned ignoreNextDoubleClick:1;
+
+    /*
+     * New stuff in Window Maker 0.95.7
+     * Added at the end of the structure to avoid breaking binary compatibility
+     * with previous versions of the toolkit
+     */
+    W_Pixmap *tristateButtonImageOn;
+    W_Pixmap *tristateButtonImageOff;
+    W_Pixmap *tristateButtonImageTri;
+
 } W_Screen;
 
 #define W_DRAWABLE(scr)		(scr)->rcontext->drawable
diff --git a/WINGs/wbutton.c b/WINGs/wbutton.c
index 8c8e4dce..c8d78d97 100644
--- a/WINGs/wbutton.c
+++ b/WINGs/wbutton.c
@@ -17,6 +17,7 @@ typedef struct W_Button {
 
 	W_Pixmap *image;
 	W_Pixmap *altImage;
+	W_Pixmap *tsImage;
 
 	W_Pixmap *dimage;
 
@@ -37,7 +38,7 @@ typedef struct W_Button {
 		WMImagePosition imagePosition:4;
 		WMAlignment alignment:2;
 
-		unsigned int selected:1;
+		unsigned int selected:2;
 
 		unsigned int enabled:1;
 
@@ -183,6 +184,14 @@ WMButton *WMCreateButton(WMWidget * parent, WMButtonType type)
 		bPtr->altImage = WMRetainPixmap(scrPtr->radioButtonImageOn);
 		break;
 
+	case WBTTriState:
+		bPtr = WMCreateCustomButton(parent, WBBStateChangeMask);
+		bPtr->flags.bordered = 0;
+		bPtr->image = WMRetainPixmap(scrPtr->tristateButtonImageOff);
+		bPtr->altImage = WMRetainPixmap(scrPtr->tristateButtonImageOn);
+		bPtr->tsImage = WMRetainPixmap(scrPtr->tristateButtonImageTri);
+		break;
+
 	default:
 	case WBTMomentaryLight:
 		bPtr = WMCreateCustomButton(parent, WBBSpringLoadedMask | WBBPushLightMask);
@@ -197,7 +206,7 @@ WMButton *WMCreateButton(WMWidget * parent, WMButtonType type)
 		WMSetButtonText(bPtr, DEFAULT_RADIO_TEXT);
 		bPtr->flags.alignment = DEFAULT_RADIO_ALIGNMENT;
 		bPtr->flags.imagePosition = DEFAULT_RADIO_IMAGE_POSITION;
-	} else if (type == WBTSwitch) {
+	} else if (type == WBTSwitch || type == WBTTriState) {
 		W_ResizeView(bPtr->view, DEFAULT_SWITCH_WIDTH, DEFAULT_SWITCH_HEIGHT);
 		WMSetButtonText(bPtr, DEFAULT_SWITCH_TEXT);
 		bPtr->flags.alignment = DEFAULT_SWITCH_ALIGNMENT;
@@ -371,7 +380,10 @@ void WMSetButtonDisabledTextColor(WMButton * bPtr, WMColor * color)
 
 void WMSetButtonSelected(WMButton * bPtr, int isSelected)
 {
-	bPtr->flags.selected = isSelected ? 1 : 0;
+	if ((bPtr->flags.type == WBTTriState) && (isSelected < 0))
+		bPtr->flags.selected = 2;
+	else
+		bPtr->flags.selected = isSelected ? 1 : 0;
 
 	if (bPtr->view->flags.realized) {
 		paintButton(bPtr);
@@ -384,6 +396,9 @@ int WMGetButtonSelected(WMButton * bPtr)
 {
 	CHECK_CLASS(bPtr, WC_Button);
 
+	if ((bPtr->flags.type == WBTTriState) && (bPtr->flags.selected == 2))
+		return -1;
+
 	return bPtr->flags.selected;
 }
 
@@ -558,7 +573,9 @@ static void paintButton(Button * bPtr)
 		if (bPtr->flags.stateChange) {
 			if (bPtr->altCaption)
 				caption = bPtr->altCaption;
-			if (bPtr->altImage)
+			if (bPtr->flags.selected == 2)
+				image = bPtr->tsImage;
+			else if (bPtr->altImage)
 				image = bPtr->altImage;
 			if (bPtr->altTextColor)
 				textColor = bPtr->altTextColor;
@@ -659,6 +676,8 @@ static void handleActionEvents(XEvent * event, void *data)
 
 	case ButtonPress:
 		if (event->xbutton.button == Button1) {
+			static const unsigned int next_state[4] = { [0] = 1, [1] = 2, [2] = 0 };
+
 			bPtr->flags.prevSelected = bPtr->flags.selected;
 			bPtr->flags.wasPushed = 0;
 			bPtr->flags.pushed = 1;
@@ -667,7 +686,10 @@ static void handleActionEvents(XEvent * event, void *data)
 				dopaint = 1;
 				break;
 			}
-			bPtr->flags.selected = !bPtr->flags.selected;
+			if (bPtr->flags.type == WBTTriState)
+				bPtr->flags.selected = next_state[bPtr->flags.selected];
+			else
+				bPtr->flags.selected = !bPtr->flags.selected;
 			dopaint = 1;
 
 			if (bPtr->flags.continuous && !bPtr->timer) {
@@ -748,5 +770,8 @@ static void destroyButton(Button * bPtr)
 	if (bPtr->altImage)
 		WMReleasePixmap(bPtr->altImage);
 
+	if (bPtr->tsImage)
+		WMReleasePixmap(bPtr->tsImage);
+
 	wfree(bPtr);
 }
diff --git a/WINGs/widgets.c b/WINGs/widgets.c
index 4c9c687f..177ad3ca 100644
--- a/WINGs/widgets.c
+++ b/WINGs/widgets.c
@@ -97,6 +97,66 @@ static char *RADIO_BUTTON_OFF[] = {
 	".....     .....",
 };
 
+#define TRISTATE_BUTTON_ON_WIDTH 	15
+#define TRISTATE_BUTTON_ON_HEIGHT	15
+static char *TRISTATE_BUTTON_ON[] = {
+	"%%%%%%%%%%%%%%.",
+	"%%%%%%%%%%%%%. ",
+	"%%           . ",
+	"%% ##     ## . ",
+	"%% ###   ### . ",
+	"%%  ### ###  . ",
+	"%%   #####   . ",
+	"%%    ###    . ",
+	"%%   #####   . ",
+	"%%  ### ###  . ",
+	"%% ###   ### . ",
+	"%% ##     ## . ",
+	"%%           . ",
+	"%............. ",
+	".              ",
+};
+
+#define TRISTATE_BUTTON_OFF_WIDTH 	15
+#define TRISTATE_BUTTON_OFF_HEIGHT	15
+static char *TRISTATE_BUTTON_OFF[] = {
+	"%%%%%%%%%%%%%%.",
+	"%%%%%%%%%%%%%. ",
+	"%%           . ",
+	"%%           . ",
+	"%%           . ",
+	"%%           . ",
+	"%%           . ",
+	"%%           . ",
+	"%%           . ",
+	"%%           . ",
+	"%%           . ",
+	"%%           . ",
+	"%%           . ",
+	"%............. ",
+	".              ",
+};
+
+#define TRISTATE_BUTTON_TRI_WIDTH 	15
+#define TRISTATE_BUTTON_TRI_HEIGHT	15
+static char *TRISTATE_BUTTON_TRI[] = {
+	"%%%%%%%%%%%%%%.",
+	"%%%%%%%%%%%%%. ",
+	"%%           . ",
+	"%% # # # # # . ",
+	"%%  # # # #  . ",
+	"%% # # # # # . ",
+	"%%  # # # #  . ",
+	"%% # # # # # . ",
+	"%%  # # # #  . ",
+	"%% # # # # # . ",
+	"%%  # # # #  . ",
+	"%% # # # # # . ",
+	"%%           . ",
+	"%............. ",
+	".              ",
+};
+
 static char *BUTTON_ARROW[] = {
 	"..................",
 	"....##....#### ...",
@@ -729,6 +789,15 @@ WMScreen *WMCreateScreenWithRContext(Display * display, int screen, RContext * c
 	scrPtr->radioButtonImageOff = makePixmap(scrPtr, RADIO_BUTTON_OFF,
 						 RADIO_BUTTON_OFF_WIDTH, RADIO_BUTTON_OFF_HEIGHT, False);
 
+	scrPtr->tristateButtonImageOn = makePixmap(scrPtr, TRISTATE_BUTTON_ON,
+	                                           TRISTATE_BUTTON_ON_WIDTH, TRISTATE_BUTTON_ON_HEIGHT, False);
+
+	scrPtr->tristateButtonImageOff = makePixmap(scrPtr, TRISTATE_BUTTON_OFF,
+	                                            TRISTATE_BUTTON_OFF_WIDTH, TRISTATE_BUTTON_OFF_HEIGHT, False);
+
+	scrPtr->tristateButtonImageTri = makePixmap(scrPtr, TRISTATE_BUTTON_TRI,
+	                                            TRISTATE_BUTTON_TRI_WIDTH, TRISTATE_BUTTON_TRI_HEIGHT, False);
+
 	scrPtr->buttonArrow = makePixmap(scrPtr, BUTTON_ARROW, BUTTON_ARROW_WIDTH, BUTTON_ARROW_HEIGHT, False);
 
 	scrPtr->pushedButtonArrow = makePixmap(scrPtr, BUTTON_ARROW2,