diff --git a/runtime/doc/gui_mac.txt b/runtime/doc/gui_mac.txt
index 769fca9766..a3d3ea729c 100644
--- a/runtime/doc/gui_mac.txt
+++ b/runtime/doc/gui_mac.txt
@@ -110,8 +110,9 @@ to your .gvimrc file to revert back to the default Vim tab label.
 
 							*macvim-options*
 These are the non-standard options that MacVim supports:
-	'antialias'	'fullscreen'		'fuoptions'
-	'macmeta'	'toolbariconsize'	'transparency'
+	'antialias'	'blurradius'	'fullscreen'
+	'fuoptions'	'macmeta'	'toolbariconsize'
+	'transparency'
 
 							*macvim-commands*
 These are the non-standard commands that MacVim supports:
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 239319e424..0bb4ae61f5 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -1169,6 +1169,14 @@ A jump table for the options with a short description can be found at |Q_op|.
 	terminal over a serial port reset this option.
 	Also see |'conskey'|.
 
+						*'blurradius'* *'blur'*
+'blurradius' 'blur'	number  (default 0)
+			global
+			{not in Vi}
+			{only in MacVim GUI}
+	When 'transparency' is in effect, a positive value adds a blur effect
+	to the window background.
+
 							*'bomb'* *'nobomb'*
 'bomb'			boolean	(default off)
 			local to buffer
diff --git a/runtime/doc/quickref.txt b/runtime/doc/quickref.txt
index 1482591dd8..74350d051b 100644
--- a/runtime/doc/quickref.txt
+++ b/runtime/doc/quickref.txt
@@ -622,6 +622,7 @@ Short explanation of each option:		*option-list*
 'balloonexpr'	  'bexpr'   expression to show in balloon
 'binary'	  'bin'     read/write/edit file in binary mode
 'bioskey'	  'biosk'   MS-DOS: use bios calls for input characters
+'blurradius'	  'blur'    transparency blur of the GUI window (MacVim only)
 'bomb'			    prepend a Byte Order Mark to the file
 'breakat'	  'brk'     characters that may cause a line break
 'breakindent'	  'bri'     wrapped line repeats indent 
diff --git a/runtime/doc/tags b/runtime/doc/tags
index d1f42a7961..91ccf21031 100644
--- a/runtime/doc/tags
+++ b/runtime/doc/tags
@@ -89,6 +89,8 @@ $VIMRUNTIME	starting.txt	/*$VIMRUNTIME*
 'bk'	options.txt	/*'bk'*
 'bkc'	options.txt	/*'bkc'*
 'bl'	options.txt	/*'bl'*
+'blur'	options.txt	/*'blur'*
+'blurradius'	options.txt	/*'blurradius'*
 'bomb'	options.txt	/*'bomb'*
 'breakat'	options.txt	/*'breakat'*
 'breakindent'	options.txt	/*'breakindent'*
diff --git a/runtime/optwin.vim b/runtime/optwin.vim
index cda6bb3a54..d9f174189c 100644
--- a/runtime/optwin.vim
+++ b/runtime/optwin.vim
@@ -645,6 +645,8 @@ if has("gui")
   if has("gui_macvim")
     call append("$", "transparency\ttransparency of the text background as a percent")
     call append("$", " \tset transparency=" . &transp)
+    call append("$", "blurradius\tblur effect of the transparent background")
+    call append("$", " \tset blurradius=" . &blur)
     call append("$", "fullscreen\tdisplay vim in fullscreen mode")
     call <SID>BinOptionG("fullscreen", &fullscreen)
     call append("$", "fuoptions\tcontrol how fullscreen mode should behave")
diff --git a/src/MacVim/CGSInternal/CGSConnection.h b/src/MacVim/CGSInternal/CGSConnection.h
new file mode 100644
index 0000000000..8e30d78c21
--- /dev/null
+++ b/src/MacVim/CGSInternal/CGSConnection.h
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2007-2008 Alacatia Labs
+ * 
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ * 
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ * 
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ * 
+ * Joe Ranieri joe@alacatia.com
+ *
+ */
+
+#pragma once
+
+#include "Compatability.h"
+
+typedef int CGSConnectionID;
+static const CGSConnectionID kCGSNullConnectionID = 0;
+
+
+CG_EXTERN_C_BEGIN
+
+/*! DOCUMENTATION PENDING - verify this is Leopard only! */
+CG_EXTERN CGError CGSSetLoginwindowConnection(CGSConnectionID cid) AVAILABLE_MAC_OS_X_VERSION_10_5_AND_LATER;
+CG_EXTERN CGError CGSSetLoginwindowConnectionWithOptions(CGSConnectionID cid, CFDictionaryRef options) AVAILABLE_MAC_OS_X_VERSION_10_5_AND_LATER;
+
+/*! Enables or disables updates on a connection. The WindowServer will forcibly reenable updates after 1 second. */
+CG_EXTERN CGError CGSDisableUpdate(CGSConnectionID cid);
+CG_EXTERN CGError CGSReenableUpdate(CGSConnectionID cid);
+
+/*! Is there a menubar associated with this connection? */
+CG_EXTERN bool CGSMenuBarExists(CGSConnectionID cid);
+
+
+
+#pragma mark notifications
+/*! Registers or removes a function to get notified when a connection is created. Only gets notified for connections created in the current application. */
+typedef void (*CGSNewConnectionNotificationProc)(CGSConnectionID cid);
+CG_EXTERN CGError CGSRegisterForNewConnectionNotification(CGSNewConnectionNotificationProc proc);
+CG_EXTERN CGError CGSRemoveNewConnectionNotification(CGSNewConnectionNotificationProc proc);
+
+/*! Registers or removes a function to get notified when a connection is released. Only gets notified for connections created in the current application. */
+typedef void (*CGSConnectionDeathNotificationProc)(CGSConnectionID cid);
+CG_EXTERN CGError CGSRegisterForConnectionDeathNotification(CGSConnectionDeathNotificationProc proc);
+CG_EXTERN CGError CGSRemoveConnectionDeathNotification(CGSConnectionDeathNotificationProc proc);
+
+/*! Creates a new connection to the window server. */
+CG_EXTERN CGError CGSNewConnection(int unused, CGSConnectionID *outConnection);
+
+/*! Releases a CGSConnection and all CGSWindows owned by it. */
+CG_EXTERN CGError CGSReleaseConnection(CGSConnectionID cid);
+
+/*! Gets the default connection for this process. `CGSMainConnectionID` is just a more modern name. */
+CG_EXTERN CGSConnectionID _CGSDefaultConnection(void);
+CG_EXTERN CGSConnectionID CGSMainConnectionID(void);
+
+/*! Gets the default connection for the current thread. */
+CG_EXTERN CGSConnectionID CGSDefaultConnectionForThread(void);
+
+/* Gets the `pid` that owns this CGSConnection. */ 
+CG_EXTERN CGError CGSConnectionGetPID(CGSConnectionID cid, pid_t *outPID);
+
+/*! Gets the CGSConnection for the PSN. */
+CG_EXTERN CGError CGSGetConnectionIDForPSN(CGSConnectionID cid, const ProcessSerialNumber *psn, CGSConnectionID *outOwnerCID);
+
+/*! Gets and sets a connection's property. */
+CG_EXTERN CGError CGSGetConnectionProperty(CGSConnectionID cid, CGSConnectionID targetCID, CFStringRef key, CFTypeRef *outValue);
+CG_EXTERN CGError CGSSetConnectionProperty(CGSConnectionID cid, CGSConnectionID targetCID, CFStringRef key, CFTypeRef value);
+
+/*! Closes ALL connections used by the current application. Essentially, it turns it into a console application. */
+CG_EXTERN CGError CGSShutdownServerConnections(void);
+
+/*! Only the owner of a window can manipulate it. So, Apple has the concept of a universal owner that owns all windows and can manipulate them all. There can only be one universal owner at a time (the Dock). */
+CG_EXTERN CGError CGSSetUniversalOwner(CGSConnectionID cid);
+
+/*! Sets a connection to be a universal owner. This call requires `cid` be a universal connection. */
+CG_EXTERN CGError CGSSetOtherUniversalConnection(CGSConnectionID cid, CGSConnectionID otherConnection);
+
+CG_EXTERN_C_END
diff --git a/src/MacVim/CGSInternal/CGSRegion.h b/src/MacVim/CGSInternal/CGSRegion.h
new file mode 100644
index 0000000000..b275c4da0b
--- /dev/null
+++ b/src/MacVim/CGSInternal/CGSRegion.h
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2007-2008 Alacatia Labs
+ * 
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ * 
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ * 
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ * 
+ * Joe Ranieri joe@alacatia.com
+ *
+ */
+
+#pragma once
+
+#pragma mark types
+#if MAC_OS_X_VERSION_10_5 <= MAC_OS_X_VERSION_MAX_ALLOWED
+	// on Leopard and up these are CFTypes
+	typedef CFTypeRef CGSRegionObj;
+	typedef CFTypeRef CGSRegionEnumeratorObj;
+#else
+	// but opaque types under 10.4
+	typedef int CGSRegionObj;
+	typedef int CGSRegionEnumeratorObj;
+#endif
+
+CG_EXTERN_C_BEGIN
+
+/*! Creates a region from a `CGRect`. */
+CG_EXTERN CGError CGSNewRegionWithRect(const CGRect *rect, CGSRegionObj *outRegion);
+
+/*! Creates a region from a list of `CGRect`s. */
+CG_EXTERN CGError CGSNewRegionWithRectList(const CGRect *rects, int rectCount, CGSRegionObj *outRegion);
+
+/*! Creates a new region from a QuickDraw region. */
+CG_EXTERN CGError CGSNewRegionWithQDRgn(RgnHandle region, CGSRegionObj *outRegion);
+
+/*! Creates an empty region. */
+CG_EXTERN CGError CGSNewEmptyRegion(CGSRegionObj *outRegion);
+
+/*! Releases a region. */
+CG_EXTERN CGError CGSReleaseRegion(CGSRegionObj region);
+
+/*! Creates a `CGRect` from a region. */
+CG_EXTERN CGError CGSGetRegionBounds(CGSRegionObj region, CGRect *outRect);
+
+/*! Determines if two regions are equal. */
+CG_EXTERN bool CGSRegionsEqual(CGSRegionObj region1, CGSRegionObj region2);
+
+/* Created a new region by changing the origin an existing one. */
+CG_EXTERN CGError CGSOffsetRegion(CGSRegionObj region, float offsetLeft, float offsetTop, CGSRegionObj *outRegion);
+
+/*! Creates a new region by copying an existing one. */
+CG_EXTERN CGError CGSCopyRegion(CGSRegionObj region, CGSRegionObj *outRegion);
+
+/*! Creates a new region by combining two regions together. */
+CG_EXTERN CGError CGSUnionRegion(CGSRegionObj region1, CGSRegionObj region2, CGSRegionObj *outRegion);
+
+/*! Creates a new region by combining a region and a rect. */
+CG_EXTERN CGError CGSUnionRegionWithRect(CGSRegionObj region, CGRect *rect, CGSRegionObj *outRegion);
+
+/*! Creates a region by XORing two regions together. */
+CG_EXTERN CGError CGSXorRegion(CGSRegionObj region1, CGSRegionObj region2, CGSRegionObj *outRegion);
+
+/*! Determines if the region is empty. */
+CG_EXTERN bool CGSRegionIsEmpty(CGSRegionObj region);
+
+/*! Determines if the region is rectangular. */
+CG_EXTERN bool CGSRegionIsRectangular(CGSRegionObj region);
+
+/*! Determines if a point in a region. */
+CG_EXTERN bool CGSPointInRegion(CGSRegionObj region, const CGPoint *point);
+
+/*! Determines if a rect is in a region. */
+CG_EXTERN bool CGSRectInRegion(CGSRegionObj region, const CGRect *rect);
+
+/*! Determines if a region is inside of a region. */
+CG_EXTERN bool CGSRegionInRegion(CGSRegionObj region1, CGSRegionObj region2);
+
+/*! Determines if a rect intersects a region. */
+CG_EXTERN bool CGSRegionIntersectsRect(CGSRegionObj obj, const CGRect *rect);
+
+/*! Determines if a region intersects a region. */
+CG_EXTERN bool CGSRegionIntersectsRegion(CGSRegionObj region1, CGSRegionObj region2);
+
+/*! Creates a rect from the difference of two regions. */
+CG_EXTERN CGError CGSDiffRegion(CGSRegionObj region1, CGSRegionObj region2, CGSRegionObj *outRegion);
+
+
+#pragma mark region enumerators
+/*! Gets the enumerator for a region. */
+CG_EXTERN CGSRegionEnumeratorObj CGSRegionEnumerator(CGSRegionObj region);
+
+/*! Releases a region enumerator. */
+CG_EXTERN void CGSReleaseRegionEnumerator(CGSRegionEnumeratorObj enumerator);
+
+/*! Gets the next rect of a region. */
+CG_EXTERN CGRect* CGSNextRect(CGSRegionEnumeratorObj enumerator);
+
+CG_EXTERN_C_END
diff --git a/src/MacVim/CGSInternal/CGSWindow.h b/src/MacVim/CGSInternal/CGSWindow.h
new file mode 100644
index 0000000000..cc72e0b0ff
--- /dev/null
+++ b/src/MacVim/CGSInternal/CGSWindow.h
@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) 2007-2008 Alacatia Labs
+ * 
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ * 
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ * 
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ * 
+ * Joe Ranieri joe@alacatia.com
+ *
+ */
+
+#pragma once
+#include "CGSConnection.h"
+#include "CGSRegion.h"
+
+typedef int CGSWindowID;
+typedef int CGSAnimationObj;
+typedef struct { CGPoint localPoint; CGPoint globalPoint; } CGSWarpPoint;
+
+typedef enum {
+	kCGSSharingNone,
+	kCGSSharingReadOnly,
+	kCGSSharingReadWrite
+} CGSSharingState;
+
+typedef enum {
+	kCGSOrderBelow = -1,
+	kCGSOrderOut, /* hides the window */
+	kCGSOrderAbove,
+	kCGSOrderIn /* shows the window */
+} CGSWindowOrderingMode;
+
+typedef enum {
+   kCGSBackingNonRetianed,
+   kCGSBackingRetained,
+   kCGSBackingBuffered,
+} CGSBackingType;
+
+
+CG_EXTERN_C_BEGIN
+
+/*! Switches to the next (or previous) window in the global list. */
+CG_EXTERN CGError CGSCycleWindows(CGSConnectionID cid, CGSWindowOrderingMode order);
+
+/*! Gets and sets the desktop window. Not sure what happens if more than one process sets the desktop window. */
+CG_EXTERN CGError CGSDesktopWindow(CGSConnectionID cid, CGSWindowID *outWID);
+CG_EXTERN CGError CGSSetDesktopWindow(CGSConnectionID cid, CGSWindowID wid);
+
+/*! Sets the window's title. Internally this simply calls `CGSSetWindowProperty(cid, wid, kCGSWindowTitle, title)`. */
+CG_EXTERN CGError CGSSetWindowTitle(CGSConnectionID cid, CGSWindowID wid, CFStringRef title);
+
+/*! Gets and sets a property for a window. */
+CG_EXTERN CGError CGSGetWindowProperty(CGSConnectionID cid, CGSWindowID wid, CFStringRef key, CFTypeRef *outValue);
+CG_EXTERN CGError CGSSetWindowProperty(CGSConnectionID cid, CGSWindowID wid, CFStringRef key, CFTypeRef value);
+
+/*! Gets and sets the window's transparency. */
+CG_EXTERN CGError CGSGetWindowAlpha(CGSConnectionID cid, CGSWindowID wid, float *outAlpha);
+CG_EXTERN CGError CGSSetWindowAlpha(CGSConnectionID cid, CGSWindowID wid, float alpha);
+
+/*! Sets the alpha of a group of windows over a period of time. Note that `duration` is in seconds. */
+CG_EXTERN CGError CGSSetWindowListAlpha(CGSConnectionID cid, const CGSWindowID *widList, int widCount, float alpha, float duration);
+
+/*! Gets and sets the `CGConnectionID` that owns this window. Only the owner can change most properties of the window. */
+CG_EXTERN CGError CGSGetWindowOwner(CGSConnectionID cid, CGSWindowID wid, CGSConnectionID *outOwner);
+CG_EXTERN CGError CGSSetWindowOwner(CGSConnectionID cid, CGSWindowID wid, CGSConnectionID owner);
+
+/*! Sets the background color of the window. */
+CG_EXTERN CGError CGSSetWindowAutofillColor(CGSConnectionID cid, CGSWindowID wid, float red, float green, float blue);
+
+/*! Locks a window to the cursor, so that whenever the cursor moves, the window moves with it. There doesn't seem to be a way to unlock the window from the cursor. */
+CG_EXTERN CGError CGSLockWindowToCursor(CGSConnectionID cid, CGSWindowID wid, float offsetLeft, float offsetTop);
+
+/*! Sets the warp for the window. The mesh maps a local (window) point to a point on screen. */
+CG_EXTERN CGError CGSSetWindowWarp(CGSConnectionID cid, CGSWindowID wid, int warpWidth, int warpHeight, const CGSWarpPoint *warp);
+
+/*! Gets or sets whether the window server should auto-fill the window's background. */
+CG_EXTERN CGError CGSGetWindowAutofill(CGSConnectionID cid, CGSWindowID wid, bool *outShouldAutoFill);
+CG_EXTERN CGError CGSSetWindowAutofill(CGSConnectionID cid, CGSWindowID wid, bool shouldAutoFill);
+
+/*! Gets the screen rect for a window. */
+CG_EXTERN CGError CGSGetScreenRectForWindow(CGSConnectionID cid, CGSWindowID wid, CGRect *outRect);
+
+/*! Gets and sets the window level for a window. */
+CG_EXTERN CGError CGSGetWindowLevel(CGSConnectionID cid, CGSWindowID wid, CGWindowLevel *outLevel);
+CG_EXTERN CGError CGSSetWindowLevel(CGSConnectionID cid, CGSWindowID wid, CGWindowLevel level);
+
+/*! Gets and sets the sharing state. This determines the level of access other applications have over this window. */
+CG_EXTERN CGError CGSGetWindowSharingState(CGSConnectionID cid, CGSWindowID wid, CGSSharingState *outState);
+CG_EXTERN CGError CGSSetWindowSharingState(CGSConnectionID cid, CGSWindowID wid, CGSSharingState state);
+
+/*! Sets whether this window is ignored in the global window cycle (Control-F4 by default). There is no Get version? */
+CG_EXTERN CGError CGSSetIgnoresCycle(CGSConnectionID cid, CGSWindowID wid, bool ignoresCycle);
+
+/*! Creates a graphics context for the window. */
+CG_EXTERN CGContextRef CGWindowContextCreate(CGSConnectionID cid, CGSWindowID wid, int unknown);
+
+/*! Sets the order of a window */
+CG_EXTERN CGError CGSOrderWindow(CGSConnectionID cid, CGSWindowID wid, CGSWindowOrderingMode mode, CGSWindowID relativeToWID);
+
+/*! Sets the origin (top-left) of a window */
+CG_EXTERN CGError CGSMoveWindow(CGSConnectionID cid, CGSWindowID wid, const CGPoint *origin);
+
+/*! Sets the origin (top-left) of a window relative to another window's origin. */
+CG_EXTERN CGError CGSSetWindowOriginRelativeToWindow(CGSConnectionID cid, CGSWindowID wid, CGSWindowID relativeToWID, float offsetX, float offsetY);
+
+/* Flushes a window's buffer to the screen. */
+CG_EXTERN CGError CGSFlushWindow(CGSConnectionID cid, CGSWindowID wid, CGSRegionObj flushRegion);
+
+
+#pragma mark shadows
+/*! Gets and sets the shadow information for a window. Values for `flags` are unknown. */
+CG_EXTERN CGError CGSSetWindowShadowAndRimParameters(CGSConnectionID cid, CGSWindowID wid, float standardDeviation, float density, int offsetX, int offsetY, int flags);
+CG_EXTERN CGError CGSGetWindowShadowAndRimParameters(CGSConnectionID cid, CGSWindowID wid, float *outStandardDeviation, float *outDensity, int *outOffsetX, int *outOffsetY, int *outFlags);
+
+/*! Sets the shadow information for a window. Simply calls through to `CGSSetWindowShadowAndRimParameters` passing 1 for `flags`. */
+CG_EXTERN CGError CGSSetWindowShadowParameters(CGSConnectionID cid, CGSWindowID wid, float standardDeviation, float density, int offsetX, int offsetY);
+
+/*! Invalidates a window's shadow. */
+CG_EXTERN CGError CGSInvalidateWindowShadow(CGSConnectionID cid, CGSWindowID wid);
+
+
+#pragma mark window lists
+/*! Gets the number of windows the `targetCID` owns. */
+CG_EXTERN CGError CGSGetWindowCount(CGSConnectionID cid, CGSConnectionID targetCID, int *outCount);
+
+/*! Gets a list of windows owned by `targetCID`. */
+CG_EXTERN CGError CGSGetWindowList(CGSConnectionID cid, CGSConnectionID targetCID, int count, CGSWindowID *list, int *outCount);
+
+/*! Gets the number of windows owned by `targetCID` that are on screen. */
+CG_EXTERN CGError CGSGetOnScreenWindowCount(CGSConnectionID cid, CGSConnectionID targetCID, int *outCount);
+
+/*! Gets a list of windows oned by `targetCID` that are on screen. */
+CG_EXTERN CGError CGSGetOnScreenWindowList(CGSConnectionID cid, CGSConnectionID targetCID, int count, CGSWindowID *list, int *outCount);
+
+
+#pragma mark window management
+/*! Creates a new CGSWindow. The real window top/left is the sum of the region's top/left and the top/left parameters. */
+CG_EXTERN CGError CGSNewWindow(CGSConnectionID cid, CGSBackingType backingType, float left, float top, CGSRegionObj region, CGSWindowID *outWID);
+
+/*! Creates a new CGSWindow. The real window top/left is the sum of the region's top/left and the top/left parameters. */
+CG_EXTERN CGError CGSNewWindowWithOpaqueShape(CGSConnectionID cid, CGSBackingType backingType, float left, float top, CGSRegionObj region, CGSRegionObj opaqueShape, int unknown, const int *tags, int tagSize, CGSWindowID *outWID);
+
+/*! Releases a CGSWindow. */
+CG_EXTERN CGError CGSReleaseWindow(CGSConnectionID cid, CGSWindowID wid);
+
+
+#pragma mark animations
+/*! Creates a Dock-style genie animation that goes from `wid` to `destinationWID`. */
+CG_EXTERN CGError CGSCreateGenieWindowAnimation(CGSConnectionID cid, CGSWindowID wid, CGSWindowID destinationWID, CGSAnimationObj *outAnimation);
+
+/*! Creates a sheet animation that's used when the parent window is brushed metal. Oddly enough, seems to be the only one used, even if the parent window isn't metal. */
+CG_EXTERN CGError CGSCreateMetalSheetWindowAnimationWithParent(CGSConnectionID cid, CGSWindowID wid, CGSWindowID parentWID, CGSAnimationObj *outAnimation);
+
+/*! Sets the progress of an animation. */
+CG_EXTERN CGError CGSSetWindowAnimationProgress(CGSAnimationObj animation, float progress);
+
+/*! DOCUMENTATION PENDING */
+CG_EXTERN CGError CGSWindowAnimationChangeLevel(CGSAnimationObj animation, CGWindowLevel level);
+
+/*! DOCUMENTATION PENDING */
+CG_EXTERN CGError CGSWindowAnimationSetParent(CGSAnimationObj animation, CGSWindowID parent) AVAILABLE_MAC_OS_X_VERSION_10_5_AND_LATER;
+
+/*! Releases a window animation. */
+CG_EXTERN CGError CGSReleaseWindowAnimation(CGSAnimationObj animation);
+
+
+#pragma mark window accelleration
+/*! Gets the state of accelleration for the window. */
+CG_EXTERN CGError CGSWindowIsAccelerated(CGSConnectionID cid, CGSWindowID wid, bool *outIsAccelerated);
+
+/*! Gets and sets if this window can be accellerated. I don't know if playing with this is safe. */
+CG_EXTERN CGError CGSWindowCanAccelerate(CGSConnectionID cid, CGSWindowID wid, bool *outCanAccelerate);
+CG_EXTERN CGError CGSWindowSetCanAccelerate(CGSConnectionID cid, CGSWindowID wid, bool canAccelerate);
+
+
+#pragma mark system status items
+/*! Registers or unregisters a window as a global status item (see `NSStatusItem`, `NSMenuExtra`). Once a window is registered, the window server takes care of placing it in the apropriate location. */
+CG_EXTERN CGError CGSRegisterWindowWithSystemStatusBar(CGSConnectionID cid, CGSWindowID wid, int priority);
+CG_EXTERN CGError CGSUnregisterWindowWithSystemStatusBar(CGSConnectionID cid, CGSWindowID wid);
+
+/*! Rearranges items in the system status bar. You should call this after registering or unregistering a status item or changing the window's width. */
+CG_EXTERN CGError CGSAdjustSystemStatusBarWindows(CGSConnectionID cid);
+
+CG_EXTERN_C_END
diff --git a/src/MacVim/CGSInternal/Compatability.h b/src/MacVim/CGSInternal/Compatability.h
new file mode 100644
index 0000000000..4912d5297a
--- /dev/null
+++ b/src/MacVim/CGSInternal/Compatability.h
@@ -0,0 +1,21 @@
+/*
+ *  Compatability.h
+ *  iTerm
+ *
+ *  Created by Marc on 10.08.10.
+ *  Copyright 2010 Marc Haisenko. All rights reserved.
+ *
+ */
+
+#pragma once
+
+#include <Carbon/Carbon.h>
+
+#ifndef CG_EXTERN_C_BEGIN
+#define CG_EXTERN_C_BEGIN
+#define CG_EXTERN_C_END
+#endif
+
+#ifndef CG_EXTERN
+#define CG_EXTERN
+#endif
diff --git a/src/MacVim/CGSInternal/README.txt b/src/MacVim/CGSInternal/README.txt
new file mode 100644
index 0000000000..34be3e1bab
--- /dev/null
+++ b/src/MacVim/CGSInternal/README.txt
@@ -0,0 +1,4 @@
+These header files were originally taken from the iTerm2 project at
+https://github.com/gnachman/iTerm2/tree/dff7c9faec90daa7f1974a57bb43d1c2d383892e/ThirdParty/CGSInternal
+
+iTerm2 is licensed under the GPL version 2.
diff --git a/src/MacVim/MMBackend.h b/src/MacVim/MMBackend.h
index ee631237d7..d1de31b424 100644
--- a/src/MacVim/MMBackend.h
+++ b/src/MacVim/MMBackend.h
@@ -137,6 +137,10 @@ extern NSTimeInterval MMBalloonEvalInternalDelay;
 
 - (void)setAntialias:(BOOL)antialias;
 
+#ifdef FEAT_TRANSPARENCY
+- (void)setBlurRadius:(int)radius;
+#endif
+
 - (void)updateModifiedFlag;
 
 - (void)registerServerWithName:(NSString *)name;
diff --git a/src/MacVim/MMBackend.m b/src/MacVim/MMBackend.m
index 7a4cded10f..81f0fedf8d 100644
--- a/src/MacVim/MMBackend.m
+++ b/src/MacVim/MMBackend.m
@@ -1180,6 +1180,18 @@ extern GuiFont gui_mch_retain_font(GuiFont font);
     [self queueMessage:msgid data:nil];
 }
 
+#ifdef FEAT_TRANSPARENCY
+
+- (void)setBlurRadius:(int)radius
+{
+    NSMutableData *data = [NSMutableData data];
+    [data appendBytes:&radius length:sizeof(int)];
+
+    [self queueMessage:SetBlurRadiusMsgID data:data];
+}
+
+#endif
+
 - (void)updateModifiedFlag
 {
     int state = [self checkForModifiedBuffers];
diff --git a/src/MacVim/MMVimController.m b/src/MacVim/MMVimController.m
index 3094e4bccb..324bab7c85 100644
--- a/src/MacVim/MMVimController.m
+++ b/src/MacVim/MMVimController.m
@@ -876,6 +876,10 @@ static BOOL isUnsafeMessage(int msgid);
         if (filenames)
             [[NSDocumentController sharedDocumentController]
                                             noteNewRecentFilePaths:filenames];
+    } else if (SetBlurRadiusMsgID == msgid) {
+        const void *bytes = [data bytes];
+        int radius = *((int*)bytes);
+        [windowController setBlurRadius:radius];
 
     // IMPORTANT: When adding a new message, make sure to update
     // isUnsafeMessage() if necessary!
diff --git a/src/MacVim/MMWindow.h b/src/MacVim/MMWindow.h
index 385a40ea33..9eb7be1cba 100644
--- a/src/MacVim/MMWindow.h
+++ b/src/MacVim/MMWindow.h
@@ -28,6 +28,7 @@
 - (void)setContentMinSize:(NSSize)size;
 - (void)setContentMaxSize:(NSSize)size;
 - (void)setContentSize:(NSSize)size;
+- (void)setBlurRadius:(int)radius;
 
 - (IBAction)toggleFullScreen:(id)sender;
 - (IBAction)realToggleFullScreen:(id)sender;
diff --git a/src/MacVim/MMWindow.m b/src/MacVim/MMWindow.m
index 1440f0a8fd..7dc42cf3b5 100644
--- a/src/MacVim/MMWindow.m
+++ b/src/MacVim/MMWindow.m
@@ -28,9 +28,39 @@
 
 #import "MMWindow.h"
 #import "Miscellaneous.h"
+#import "CGSInternal/CGSWindow.h"
 
 
 
+typedef CGError CGSSetWindowBackgroundBlurRadiusFunction(CGSConnectionID cid, CGSWindowID wid, NSUInteger blur);
+
+static void *GetFunctionByName(NSString *library, char *func) {
+    CFBundleRef bundle;
+    CFURLRef bundleURL = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, (CFStringRef) library, kCFURLPOSIXPathStyle, true);
+    CFStringRef functionName = CFStringCreateWithCString(kCFAllocatorDefault, func, kCFStringEncodingASCII);
+    bundle = CFBundleCreate(kCFAllocatorDefault, bundleURL);
+    void *f = NULL;
+    if (bundle) {
+        f = CFBundleGetFunctionPointerForName(bundle, functionName);
+        CFRelease(bundle);
+    }
+    CFRelease(functionName);
+    CFRelease(bundleURL);
+    return f;
+}
+
+static CGSSetWindowBackgroundBlurRadiusFunction* GetCGSSetWindowBackgroundBlurRadiusFunction(void) {
+    static BOOL tried = NO;
+    static CGSSetWindowBackgroundBlurRadiusFunction *function = NULL;
+    if (!tried) {
+        function = GetFunctionByName(@"/System/Library/Frameworks/ApplicationServices.framework",
+                                      "CGSSetWindowBackgroundBlurRadius");
+        tried = YES;
+    }
+    return function;
+}
+
+
 
 @implementation MMWindow
 
@@ -125,6 +155,20 @@
     [super setContentSize:size];
 }
 
+- (void)setBlurRadius:(int)radius
+{
+    if (radius >= 0) {
+        CGSConnectionID con = CGSMainConnectionID();
+        if (!con) {
+            return;
+        }
+        CGSSetWindowBackgroundBlurRadiusFunction* function = GetCGSSetWindowBackgroundBlurRadiusFunction();
+        if (function) {
+            function(con, [self windowNumber], radius);
+        }
+    }
+}
+
 - (void)performClose:(id)sender
 {
     id wc = [self windowController];
diff --git a/src/MacVim/MMWindowController.h b/src/MacVim/MMWindowController.h
index a200c16cdc..8874bb03e5 100644
--- a/src/MacVim/MMWindowController.h
+++ b/src/MacVim/MMWindowController.h
@@ -46,6 +46,7 @@
     NSPoint             defaultTopLeft;
     NSToolbar           *toolbar;
     BOOL                resizingDueToMove;
+    int                 blurRadius;
 }
 
 - (id)initWithVimController:(MMVimController *)controller;
@@ -81,6 +82,7 @@
 - (void)adjustLinespace:(int)linespace;
 - (void)liveResizeWillStart;
 - (void)liveResizeDidEnd;
+- (void)setBlurRadius:(int)radius;
 
 - (void)enterFullScreen:(int)fuoptions backgroundColor:(NSColor *)back;
 - (void)leaveFullScreen;
diff --git a/src/MacVim/MMWindowController.m b/src/MacVim/MMWindowController.m
index ecb9008e73..2d04397474 100644
--- a/src/MacVim/MMWindowController.m
+++ b/src/MacVim/MMWindowController.m
@@ -330,6 +330,8 @@
     if (fullScreenEnabled && !fullScreenWindow)
         [decoratedWindow setAlphaValue:0];
 
+    [decoratedWindow setBlurRadius:blurRadius];
+
     // Flag that the window is now placed on screen.  From now on it is OK for
     // code to depend on the screen state.  (Such as constraining views etc.)
     windowPresented = YES;
@@ -719,6 +721,14 @@
     }
 }
 
+- (void)setBlurRadius:(int)radius
+{
+    blurRadius = radius;
+    if (windowPresented) { 
+        [decoratedWindow setBlurRadius:radius];
+    }
+}
+
 - (void)enterFullScreen:(int)fuoptions backgroundColor:(NSColor *)back
 {
     if (fullScreenEnabled) return;
diff --git a/src/MacVim/MacVim.h b/src/MacVim/MacVim.h
index 6531534e0c..6d1135081b 100644
--- a/src/MacVim/MacVim.h
+++ b/src/MacVim/MacVim.h
@@ -208,6 +208,7 @@ enum {
     GestureMsgID,
     AddToMRUMsgID,
     BackingPropertiesChangedMsgID,
+    SetBlurRadiusMsgID,
     LastMsgID   // NOTE: MUST BE LAST MESSAGE IN ENUM!
 };
 
diff --git a/src/MacVim/MacVim.m b/src/MacVim/MacVim.m
index f1311f4262..3b6b4e0428 100644
--- a/src/MacVim/MacVim.m
+++ b/src/MacVim/MacVim.m
@@ -100,6 +100,7 @@ char *MessageStrings[] =
     "GestureMsgID",
     "AddToMRUMsgID",
     "BackingPropertiesChangedMsgID",
+    "SetBlurRadiusMsgID",
     "END OF MESSAGE IDs"     // NOTE: Must be last!
 };
 
diff --git a/src/MacVim/gui_macvim.m b/src/MacVim/gui_macvim.m
index dc62e2eecf..0ad8492d2f 100644
--- a/src/MacVim/gui_macvim.m
+++ b/src/MacVim/gui_macvim.m
@@ -2359,3 +2359,13 @@ gui_mch_post_balloon(beval, mesg)
 }
 
 #endif // FEAT_BEVAL
+
+#ifdef FEAT_TRANSPARENCY
+
+    void
+gui_macvim_set_blur(int radius)
+{
+    [[MMBackend sharedInstance] setBlurRadius:radius];
+}
+
+#endif // FEAT_TRANSPARENCY
diff --git a/src/option.c b/src/option.c
index c69daf65ea..cc19e67519 100644
--- a/src/option.c
+++ b/src/option.c
@@ -646,6 +646,13 @@ static struct vimoption
 			    (char_u *)NULL, PV_NONE,
 #endif
 			    {(char_u *)TRUE, (char_u *)0L} SCRIPTID_INIT},
+    {"blurradius",  "blur", P_NUM|P_VIM,
+#ifdef FEAT_TRANSPARENCY
+			    (char_u *)&p_blur, PV_NONE,
+#else
+			    (char_u *)NULL, PV_NONE,
+#endif
+			    {(char_u *)0L, (char_u *)0L} },
     {"bomb",	    NULL,   P_BOOL|P_NO_MKRC|P_VI_DEF|P_RSTAT,
 #ifdef FEAT_MBYTE
 			    (char_u *)&p_bomb, PV_BOMB,
@@ -8706,6 +8713,19 @@ set_num_option(opt_idx, varp, value, errbuf, errbuflen, opt_flags)
         else if (gui.in_use)
             gui_mch_new_colors();
     }
+
+    else if (pp == &p_blur)
+    {
+        if (p_blur < 0)
+        {
+            errmsg = e_invarg;
+            p_blur = old_value;
+        }
+        else
+        {
+            gui_macvim_set_blur(p_blur);
+        }
+    }
 #endif
 
     else if (pp == &curbuf->b_p_tw)
diff --git a/src/option.h b/src/option.h
index 85e8dc38b6..838cdce016 100644
--- a/src/option.h
+++ b/src/option.h
@@ -811,6 +811,7 @@ EXTERN char_u	*p_tsr;		/* 'thesaurus' */
 #endif
 #ifdef FEAT_TRANSPARENCY
 EXTERN long     p_transp;       /* 'transparency' */
+EXTERN long     p_blur;         /* 'blurradius' */
 #endif
 EXTERN int	p_ttimeout;	/* 'ttimeout' */
 EXTERN long	p_ttm;		/* 'ttimeoutlen' */
diff --git a/src/proto/gui_macvim.pro b/src/proto/gui_macvim.pro
index 427205d76f..6443a62f35 100644
--- a/src/proto/gui_macvim.pro
+++ b/src/proto/gui_macvim.pro
@@ -208,6 +208,10 @@ void gui_macvim_update_modified_flag();
 void gui_macvim_add_to_find_pboard(char_u *pat);
 void gui_macvim_set_antialias(int antialias);
 
+#ifdef FEAT_TRANSPARENCY
+void gui_macvim_set_blur(int blur);
+#endif
+
 int16_t odb_buffer_close(buf_T *buf);
 int16_t odb_post_buffer_write(buf_T *buf);
 void odb_end(void);