diff -ur xorg-server.orig/configure.ac xorg-server/configure.ac
--- xorg-server.orig/configure.ac	2016-04-09 21:28:27.007999965 +0200
+++ xorg-server/configure.ac	2016-04-09 21:28:57.587999860 +0200
@@ -74,6 +74,7 @@
 AC_CONFIG_HEADERS(include/version-config.h)
 
 AM_PROG_AS
+AC_PROG_CXX
 AC_PROG_LN_S
 LT_PREREQ([2.2])
 LT_INIT([disable-static win32-dll])
@@ -1828,6 +1829,10 @@
 	AC_SUBST([XVFB_SYS_LIBS])
 fi
 
+dnl Xvnc DDX
+AC_SUBST([XVNC_CPPFLAGS], ["-DHAVE_DIX_CONFIG_H $XSERVER_CFLAGS"])
+AC_SUBST([XVNC_LIBS], ["$FB_LIB $FIXES_LIB $XEXT_LIB $CONFIG_LIB $DBE_LIB $RECORD_LIB $GLX_LIBS $RANDR_LIB $RENDER_LIB $DAMAGE_LIB $DRI3_LIB $PRESENT_LIB $MIEXT_SYNC_LIB $MIEXT_DAMAGE_LIB $MIEXT_SHADOW_LIB $XI_LIB $XKB_LIB $XKB_STUB_LIB $COMPOSITE_LIB $MAIN_LIB"])
+AC_SUBST([XVNC_SYS_LIBS], ["$GLX_SYS_LIBS"])
 
 dnl Xnest DDX
 
@@ -1863,6 +1868,8 @@
 fi
 AC_MSG_RESULT([$XORG])
 
+AC_DEFINE_UNQUOTED(XORG_VERSION_CURRENT, [$VENDOR_RELEASE], [Current Xorg version])
+
 if test "x$XORG" = xyes; then
 	XORG_DDXINCS='-I$(top_srcdir)/hw/xfree86 -I$(top_srcdir)/hw/xfree86/include -I$(top_srcdir)/hw/xfree86/common'
 	XORG_OSINCS='-I$(top_srcdir)/hw/xfree86/os-support -I$(top_srcdir)/hw/xfree86/os-support/bus -I$(top_srcdir)/os'
@@ -2081,7 +2088,6 @@
 	AC_DEFINE(XORG_SERVER, 1, [Building Xorg server])
 	AC_DEFINE(XORGSERVER, 1, [Building Xorg server])
 	AC_DEFINE(XFree86Server, 1, [Building XFree86 server])
-	AC_DEFINE_UNQUOTED(XORG_VERSION_CURRENT, [$VENDOR_RELEASE], [Current Xorg version])
 	AC_DEFINE(NEED_XF86_TYPES, 1, [Need XFree86 typedefs])
 	AC_DEFINE(NEED_XF86_PROTOTYPES, 1, [Need XFree86 helper functions])
 	AC_DEFINE(__XSERVERNAME__, "Xorg", [Name of X server])
@@ -2653,6 +2659,7 @@
 hw/dmx/man/Makefile
 hw/vfb/Makefile
 hw/vfb/man/Makefile
+hw/vnc/Makefile
 hw/xnest/Makefile
 hw/xnest/man/Makefile
 hw/xwin/Makefile
diff -ur xorg-server.orig/hw/Makefile.am xorg-server/hw/Makefile.am
--- xorg-server.orig/hw/Makefile.am	2016-04-09 21:28:27.059999965 +0200
+++ xorg-server/hw/Makefile.am	2016-04-09 21:28:57.587999860 +0200
@@ -43,6 +43,7 @@
 	$(KDRIVE_SUBDIRS)	\
 	$(XQUARTZ_SUBDIRS)	\
-	$(XWAYLAND_SUBDIRS)
+	$(XWAYLAND_SUBDIRS) \
+	vnc
 
 DIST_SUBDIRS = dmx xfree86 vfb xnest xwin xquartz kdrive xwayland
 
diff -ur xorg-server.orig/mi/miinitext.c xorg-server/mi/miinitext.c
--- xorg-server.orig/mi/miinitext.c	2016-04-09 21:28:27.015999965 +0200
+++ xorg-server/mi/miinitext.c	2016-04-09 21:28:57.587999860 +0200
@@ -114,6 +114,10 @@
 #include "micmap.h"
 #include "globals.h"
 
+#ifdef KASMVNC
+extern void vncExtensionInit(void);
+#endif
+
 /* The following is only a small first step towards run-time
  * configurable extensions.
  */
@@ -238,6 +242,9 @@
 
 /* List of built-in (statically linked) extensions */
 static const ExtensionModule staticExtensions[] = {
+#ifdef KASMVNC
+    {vncExtensionInit, "VNC-EXTENSION", NULL},
+#endif
     {GEExtensionInit, "Generic Event Extension", &noGEExtension},
     {ShapeExtensionInit, "SHAPE", NULL},
 #ifdef MITSHM
diff -ur xorg-server.orig/os/WaitFor.c xorg-server/os/WaitFor.c
--- xorg-server.orig/os/WaitFor.c	2016-04-09 21:28:27.071999965 +0200
+++ xorg-server/os/WaitFor.c	2016-04-09 21:28:57.587999860 +0200
@@ -125,6 +125,9 @@
 static void CheckAllTimers(void);
 static volatile OsTimerPtr timers = NULL;
 
+extern void vncWriteBlockHandler(fd_set *fds);
+extern void vncWriteWakeupHandler(int nfds, fd_set *fds);
+
 /*****************
  * WaitForSomething:
  *     Make the server suspend until there is
@@ -150,6 +153,7 @@
     INT32 timeout = 0;
     fd_set clientsReadable;
     fd_set clientsWritable;
+    fd_set socketsWritable;
     int curclient;
     int selecterr;
     static int nready;
@@ -213,6 +217,9 @@
             XFD_COPYSET(&AllSockets, &LastSelectMask);
         }
 
+        FD_ZERO(&socketsWritable);
+        vncWriteBlockHandler(&socketsWritable);
+
         BlockHandler((void *) &wt, (void *) &LastSelectMask);
         if (NewOutputPending)
             FlushAllOutput();
@@ -224,10 +231,20 @@
             i = Select(MaxClients, &LastSelectMask, &clientsWritable, NULL, wt);
         }
         else {
-            i = Select(MaxClients, &LastSelectMask, NULL, NULL, wt);
+	    if (AnyClientsWriteBlocked)
+		XFD_ORSET(&socketsWritable, &ClientsWriteBlocked, &socketsWritable);
+
+	    if (XFD_ANYSET(&socketsWritable)) {
+		i = Select(MaxClients, &LastSelectMask, &socketsWritable, NULL, wt);
+		if (AnyClientsWriteBlocked)
+		    XFD_ANDSET(&clientsWritable, &socketsWritable, &ClientsWriteBlocked);
+	    } else {
+		i = Select(MaxClients, &LastSelectMask, NULL, NULL, wt);
+	    }
         }
         selecterr = GetErrno();
         WakeupHandler(i, (void *) &LastSelectMask);
+	vncWriteWakeupHandler(i, &socketsWritable);
         if (i <= 0) {           /* An error or timeout occurred */
             if (dispatchException)
                 return 0;
