diff --git a/darwin/CMakeLists.txt b/darwin/CMakeLists.txt
index 2bc34ec9..f0c936b5 100644
--- a/darwin/CMakeLists.txt
+++ b/darwin/CMakeLists.txt
@@ -39,6 +39,7 @@ list(APPEND _LIBUI_SOURCES
 	darwin/text.m
 	darwin/util.m
 	darwin/window.m
+	darwin/winmoveresize.m
 )
 set(_LIBUI_SOURCES ${_LIBUI_SOURCES} PARENT_SCOPE)
 
diff --git a/darwin/area.m b/darwin/area.m
index 6c6ac4b7..6929f292 100644
--- a/darwin/area.m
+++ b/darwin/area.m
@@ -32,6 +32,7 @@ struct uiArea {
 	struct scrollViewData *d;
 	uiAreaHandler *ah;
 	BOOL scrolling;
+	NSEvent *dragevent;
 };
 
 @implementation areaView
@@ -200,8 +201,12 @@ struct uiArea {
 			me.Held1To64 |= j;
 	}
 
-	if (self->libui_enabled)
+	if (self->libui_enabled) {
+		// and allow dragging here
+		a->dragevent = e;
 		(*(a->ah->MouseEvent))(a->ah, a, &me);
+		a->dragevent = nil;
+	}
 }
 
 #define mouseEvent(name) \
@@ -403,12 +408,26 @@ void uiAreaScrollTo(uiArea *a, double x, double y, double width, double height)
 
 void uiAreaBeginUserWindowMove(uiArea *a)
 {
-	// TODO
+	libuiNSWindow *w;
+
+	w = (libuiNSWindow *) [a->area window];
+	if (w == nil)
+		return;		// TODO
+	if (a->dragevent == nil)
+		return;		// TODO
+	[w libui_doMove:a->dragevent];
 }
 
 void uiAreaBeginUserWindowResize(uiArea *a, uiWindowResizeEdge edge)
 {
-	// TODO
+	libuiNSWindow *w;
+
+	w = (libuiNSWindow *) [a->area window];
+	if (w == nil)
+		return;		// TODO
+	if (a->dragevent == nil)
+		return;		// TODO
+	[w libui_doResize:a->dragevent on:edge];
 }
 
 uiArea *uiNewArea(uiAreaHandler *ah)
diff --git a/darwin/uipriv_darwin.h b/darwin/uipriv_darwin.h
index eca2d9b0..7332b050 100644
--- a/darwin/uipriv_darwin.h
+++ b/darwin/uipriv_darwin.h
@@ -138,3 +138,6 @@ extern NSTextField *newLabel(NSString *str);
 
 // image.m
 extern NSImage *imageImage(uiImage *);
+
+// winmoveresize.m
+extern void doManualResize(NSWindow *w, NSEvent *initialEvent, uiWindowResizeEdge edge);
diff --git a/darwin/window.m b/darwin/window.m
index 4164f07a..8456c767 100644
--- a/darwin/window.m
+++ b/darwin/window.m
@@ -27,7 +27,7 @@ struct uiWindow {
 
 - (void)libui_doResize:(NSEvent *)initialEvent on:(uiWindowResizeEdge)edge
 {
-	// TODO
+	doManualResize(self, initialEvent, edge);
 }
 
 @end
diff --git a/darwin/winmoveresize.m b/darwin/winmoveresize.m
new file mode 100644
index 00000000..58155683
--- /dev/null
+++ b/darwin/winmoveresize.m
@@ -0,0 +1,210 @@
+// 1 november 2016
+#import "uipriv_darwin.h"
+
+// see http://stackoverflow.com/a/40352996/3408572
+static void minMaxAutoLayoutSizes(NSWindow *w, NSSize *min, NSSize *max)
+{
+	NSLayoutConstraint *cw, *ch;
+	NSView *contentView;
+	NSRect prevFrame;
+
+	// if adding these constraints causes the window to change size somehow, don't show it to the user and change it back afterwards
+	NSDisableScreenUpdates();
+	prevFrame = [w frame];
+
+	// minimum: encourage the window to be as small as possible
+	contentView = [w contentView];
+	cw = mkConstraint(contentView, NSLayoutAttributeWidth,
+		NSLayoutRelationEqual,
+		nil, NSLayoutAttributeNotAnAttribute,
+		0, 0,
+		@"window minimum width finding constraint");
+	[cw setPriority:NSLayoutPriorityDragThatCanResizeWindow];
+	[contentView addConstraint:cw];
+	ch = mkConstraint(contentView, NSLayoutAttributeHeight,
+		NSLayoutRelationEqual,
+		nil, NSLayoutAttributeNotAnAttribute,
+		0, 0,
+		@"window minimum height finding constraint");
+	[ch setPriority:NSLayoutPriorityDragThatCanResizeWindow];
+	[contentView addConstraint:ch];
+	*min = [contentView fittingSize];
+	[contentView removeConstraint:cw];
+	[contentView removeConstraint:ch];
+
+	// maximum: encourage the window to be as large as possible
+	contentView = [w contentView];
+	cw = mkConstraint(contentView, NSLayoutAttributeWidth,
+		NSLayoutRelationEqual,
+		nil, NSLayoutAttributeNotAnAttribute,
+		0, DBL_MAX,
+		@"window maximum width finding constraint");
+	[cw setPriority:NSLayoutPriorityDragThatCanResizeWindow];
+	[contentView addConstraint:cw];
+	ch = mkConstraint(contentView, NSLayoutAttributeHeight,
+		NSLayoutRelationEqual,
+		nil, NSLayoutAttributeNotAnAttribute,
+		0, DBL_MAX,
+		@"window maximum height finding constraint");
+	[ch setPriority:NSLayoutPriorityDragThatCanResizeWindow];
+	[contentView addConstraint:ch];
+	*max = [contentView fittingSize];
+	[contentView removeConstraint:cw];
+	[contentView removeConstraint:ch];
+
+	[w setFrame:prevFrame display:YES];		// TODO really YES?
+	NSEnableScreenUpdates();
+}
+
+static void handleResizeLeft(NSRect *frame, NSPoint old, NSPoint new)
+{
+	frame->origin.x += new.x - old.x;
+}
+
+// TODO properly handle crossing the menubar; this just stops at the menubar
+static void handleResizeTop(NSRect *frame, NSPoint old, NSPoint new)
+{
+	CGFloat offset;
+	CGFloat newHeight;
+	CGFloat oldTop, newTop;
+	NSRect mainWorkArea;
+	CGFloat menubarBottom;
+
+	offset = new.y - old.y;
+	newHeight = frame->size.height + offset;
+
+	// we have gone too high if we started under the menubar AND we are about to cross it
+	oldTop = frame->origin.y + frame->size.height;
+	newTop = frame->origin.y + newHeight;
+	mainWorkArea = [[NSScreen mainScreen] visibleFrame];
+	menubarBottom = mainWorkArea.origin.y + mainWorkArea.size.height;
+	if (oldTop < menubarBottom)
+		if (newTop >= menubarBottom)
+			return;
+
+	frame->size.height = newHeight;
+}
+
+static void handleResizeRight(NSRect *frame, NSPoint old, NSPoint new)
+{
+	frame->size.width += new.x - old.x;
+}
+
+
+// TODO properly handle crossing the menubar; this just stops at the menubar
+static void handleResizeBottom(NSRect *frame, NSPoint old, NSPoint new)
+{
+	CGFloat offset;
+	CGFloat newY;
+	NSRect mainFrame;
+	CGFloat menubarTop;
+
+	offset = new.y - old.y;
+	newY = frame->origin.y + offset;
+
+	// we have gone too low if we started above the menubar AND we are about to cross it
+	mainFrame = [[NSScreen mainScreen] frame];
+	menubarTop = mainFrame.origin.y + mainFrame.size.height;
+	if (frame->origin.y >= menubarTop)
+		if (newY < menubarTop)
+			return;
+
+	frame->origin.y = newY;
+}
+
+struct onResizeDragParams {
+	NSWindow *w;
+	NSPoint old;
+	uiWindowResizeEdge edge;
+	NSSize min;
+	NSSize max;
+};
+
+static void onResizeDrag(struct onResizeDragParams *p, NSEvent *e)
+{
+	NSPoint new;
+	NSRect frame;
+
+	new = [e locationInWindow];
+	frame = [p->w frame];
+
+NSLog(@"old %@ new %@", NSStringFromPoint(p->old), NSStringFromPoint(new));
+NSLog(@"frame %@", NSStringFromRect(frame));
+
+	// horizontal
+	switch (p->edge) {
+	case uiWindowResizeEdgeLeft:
+	case uiWindowResizeEdgeTopLeft:
+	case uiWindowResizeEdgeBottomLeft:
+		handleResizeLeft(&frame, p->old, new);
+		break;
+	case uiWindowResizeEdgeRight:
+	case uiWindowResizeEdgeTopRight:
+	case uiWindowResizeEdgeBottomRight:
+		handleResizeRight(&frame, p->old, new);
+		break;
+	}
+	// vertical
+	switch (p->edge) {
+	case uiWindowResizeEdgeTop:
+	case uiWindowResizeEdgeTopLeft:
+	case uiWindowResizeEdgeTopRight:
+		handleResizeTop(&frame, p->old, new);
+		break;
+	case uiWindowResizeEdgeBottom:
+	case uiWindowResizeEdgeBottomLeft:
+	case uiWindowResizeEdgeBottomRight:
+		handleResizeBottom(&frame, p->old, new);
+		break;
+	}
+
+	// constrain
+	if (frame.size.width < p->min.width)
+		frame.size.width = p->min.width;
+	if (frame.size.height < p->min.height)
+		frame.size.height = p->min.height;
+	// TODO > or >= ?
+	if (frame.size.width > p->max.width)
+		frame.size.width = p->max.width;
+	if (frame.size.height > p->max.height)
+		frame.size.height = p->max.height;
+
+NSLog(@"becomes %@", NSStringFromRect(frame));
+
+	[p->w setFrame:frame display:YES];			// and do reflect the new frame immediately
+	// and set it up for the next run
+	p->old = new;
+}
+
+void doManualResize(NSWindow *w, NSEvent *initialEvent, uiWindowResizeEdge edge)
+{
+	__block struct onResizeDragParams rdp;
+	struct nextEventArgs nea;
+	BOOL (^handleEvent)(NSEvent *e);
+	__block BOOL done;
+
+	rdp.w = w;
+	rdp.old = [initialEvent locationInWindow];
+	rdp.edge = edge;
+	// TODO what happens if these change during the loop?
+	minMaxAutoLayoutSizes(rdp.w, &(rdp.min), &(rdp.max));
+NSLog(@"min %@", NSStringFromSize(rdp.min));
+NSLog(@"max %@", NSStringFromSize(rdp.max));
+
+	nea.mask = NSLeftMouseDraggedMask | NSLeftMouseUpMask;
+	nea.duration = [NSDate distantFuture];
+	nea.mode = NSEventTrackingRunLoopMode;		// nextEventMatchingMask: docs suggest using this for manual mouse tracking
+	nea.dequeue = YES;
+	handleEvent = ^(NSEvent *e) {
+		if ([e type] == NSLeftMouseUp) {
+			done = YES;
+			return YES;	// do not send
+		}
+		onResizeDrag(&rdp, e);
+		return YES;		// do not send
+	};
+	done = NO;
+	while (mainStep(&nea, handleEvent))
+		if (done)
+			break;
+}