diff --git a/configure.ac b/configure.ac
index 211689d2..25a83628 100644
--- a/configure.ac
+++ b/configure.ac
@@ -580,6 +580,18 @@ AS_IF([test "x$enable_wmreplace" = "xyes"],
        [define to support ICCCM protocol for window manager replacement])
      supported_xext="$supported_xext WMReplace"])
 
+dnl XRes support
+dnl ==============
+m4_divert_push([INIT_PREPARE])dnl
+AC_ARG_ENABLE([res],
+    [AS_HELP_STRING([--disable-res], [disable resource window extension support])],
+    [AS_CASE(["$enableval"],
+        [yes|no], [],
+        [AC_MSG_ERROR([bad value $enableval for --enable-res]) ]) ],
+    [enable_res=auto])
+m4_divert_pop([INIT_PREPARE])dnl
+
+WM_XEXT_CHECK_XRES
 
 dnl XShape support
 dnl ==============
diff --git a/m4/wm_xext_check.m4 b/m4/wm_xext_check.m4
index 9503af2c..751d8314 100644
--- a/m4/wm_xext_check.m4
+++ b/m4/wm_xext_check.m4
@@ -16,6 +16,33 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
+# WM_XEXT_CHECK_XRES
+# --------------------
+#
+# Check for the X Resource Window extension
+# The check depends on variable 'enable_xshape' being either:
+#   yes  - detect, fail if not found
+#   no   - do not detect, disable support
+#   auto - detect, disable if not found
+#
+# When found, append appropriate stuff in XLIBS, and append info to
+# the variable 'supported_xext'
+# When not found, append info to variable 'unsupported'
+AC_DEFUN_ONCE([WM_XEXT_CHECK_XRES],
+[WM_LIB_CHECK([XRes], [-lXRes], [XResQueryClientIds], [$XLIBS],
+    [wm_save_CFLAGS="$CFLAGS"
+     AC_COMPILE_IFELSE([AC_LANG_PROGRAM([dnl
+@%:@include <X11/extensions/XRes.h>
+], [dnl
+
+  XResQueryClientIds(NULL, 0, NULL, NULL, NULL);])]
+        [],
+        [AC_MSG_ERROR([found $CACHEVAR but cannot compile using XRes header])])
+     CFLAGS="$wm_save_CFLAGS"],
+    [supported_xext], [XLIBS], [enable_res], [-])dnl
+]) dnl AC_DEFUN
+
+
 # WM_XEXT_CHECK_XSHAPE
 # --------------------
 #
diff --git a/src/main.c b/src/main.c
index bf5b1a0a..998bbcc5 100644
--- a/src/main.c
+++ b/src/main.c
@@ -56,6 +56,7 @@
 #include "dialog.h"
 #include "main.h"
 #include "monitor.h"
+#include "misc.h"
 
 #include <WINGs/WUtil.h>
 
@@ -354,11 +355,19 @@ Bool RelaunchWindow(WWindow *wwin)
 
 	char **argv;
 	int argc;
+	char *command = NULL;
 
-	if (! XGetCommand(dpy, wwin->client_win, &argv, &argc) || argc == 0 || argv == NULL) {
+	command = GetCommandForWindow(wwin->client_win);
+	if (!command) {
+#ifdef USE_XRES
+		werror("cannot relaunch the application because no associated process found");
+#else
 		werror("cannot relaunch the application because no WM_COMMAND property is set");
+#endif
 		return False;
-	}
+	} else
+		wtokensplit(command, &argv, &argc);
+
 
 	pid_t pid = fork();
 
@@ -384,18 +393,19 @@ Bool RelaunchWindow(WWindow *wwin)
 	} else if (pid < 0) {
 		werror("cannot fork a new process");
 
-		XFreeStringList(argv);
+		wfree(argv);
+		wfree(command);
 		return False;
 	} else {
 		_tuple *data = wmalloc(sizeof(_tuple));
 
 		data->scr = wwin->screen_ptr;
-		data->command = wtokenjoin(argv, argc);
+		data->command = command;
 
 		/* not actually a shell command */
 		wAddDeathHandler(pid, shellCommandHandler, data);
 
-		XFreeStringList(argv);
+		wfree(argv);
 	}
 
 	return True;
diff --git a/src/window.c b/src/window.c
index 59721b39..ef85f3d4 100644
--- a/src/window.c
+++ b/src/window.c
@@ -29,6 +29,9 @@
 #ifdef KEEP_XKB_LOCK_STATUS
 #include <X11/XKBlib.h>
 #endif	  /* KEEP_XKB_LOCK_STATUS */
+#ifdef USE_XRES
+#include <X11/extensions/XRes.h>
+#endif
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -475,6 +478,41 @@ Bool wWindowObscuresWindow(WWindow *wwin, WWindow *obscured)
 	return True;
 }
 
+/* Get the corresponding Process Identification Number of the active window */
+static pid_t getWindowPid(Window win)
+{
+	pid_t pid = -1;
+
+	pid = wNETWMGetPidForWindow(win);
+#ifdef USE_XRES
+	if (pid > 0)
+		return pid;
+	else {
+		XResClientIdSpec spec;
+		int status;
+		long i, num_ids = 0;
+		XResClientIdValue *client_ids = NULL;
+
+		spec.client = win;
+		spec.mask = XRES_CLIENT_ID_PID_MASK;
+
+		status = XResQueryClientIds(dpy, 1, &spec, &num_ids, &client_ids);
+
+		if (status != Success)
+			return -1;
+
+		for (i = 0; i < num_ids; i++) {
+			if (client_ids[i].spec.mask == XRES_CLIENT_ID_PID_MASK) {
+				pid = XResGetClientPid(&client_ids[i]);
+				break;
+			}
+		}
+		XResClientIdsDestroy(num_ids, client_ids);
+	}
+#endif
+	return pid;
+}
+
 static void fixLeaderProperties(WWindow *wwin)
 {
 	XClassHint *classHint;
@@ -487,7 +525,7 @@ static void fixLeaderProperties(WWindow *wwin)
 
 	classHint = XAllocClassHint();
 	clientHints = XGetWMHints(dpy, wwin->client_win);
-	pid = wNETWMGetPidForWindow(wwin->client_win);
+	pid = getWindowPid(wwin->client_win);
 	if (pid > 0)
 		haveCommand = GetCommandForPid(pid, &argv, &argc);
 	else