diff --git a/layout/xul/base/public/Makefile.in b/layout/xul/base/public/Makefile.in
new file mode 100644
index 00000000000..0b5687226c4
--- /dev/null
+++ b/layout/xul/base/public/Makefile.in
@@ -0,0 +1,35 @@
+#!gmake
+#
+# The contents of this file are subject to the Netscape Public License
+# Version 1.0 (the "NPL"); you may not use this file except in
+# compliance with the NPL.  You may obtain a copy of the NPL at
+# http://www.mozilla.org/NPL/
+#
+# Software distributed under the NPL is distributed on an "AS IS" basis,
+# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
+# for the specific language governing rights and limitations under the
+# NPL.
+#
+# The Initial Developer of this code under the NPL is Netscape
+# Communications Corporation.  Portions created by Netscape are
+# Copyright (C) 1998 Netscape Communications Corporation.  All Rights
+# Reserved.
+
+DEPTH = ../../../..
+topsrcdir	= @top_srcdir@
+srcdir		= @srcdir@
+VPATH		= @srcdir@
+
+include $(DEPTH)/config/autoconf.mk
+
+MODULE=layout
+
+EXPORTS =				\
+	nsIPopupSetFrame.h			\
+        $(NULL)
+
+EXPORTS := $(addprefix $(srcdir)/, $(EXPORTS))
+
+include $(topsrcdir)/config/config.mk
+
+include $(topsrcdir)/config/rules.mk
diff --git a/layout/xul/base/public/Manifest b/layout/xul/base/public/Manifest
new file mode 100644
index 00000000000..db6c3d7f4ea
--- /dev/null
+++ b/layout/xul/base/public/Manifest
@@ -0,0 +1,2 @@
+nsIPopupSetFrame.h
+
diff --git a/layout/xul/base/public/makefile.win b/layout/xul/base/public/makefile.win
new file mode 100644
index 00000000000..283538b0445
--- /dev/null
+++ b/layout/xul/base/public/makefile.win
@@ -0,0 +1,26 @@
+#!nmake
+#
+# The contents of this file are subject to the Netscape Public License
+# Version 1.0 (the "NPL"); you may not use this file except in
+# compliance with the NPL.  You may obtain a copy of the NPL at
+# http://www.mozilla.org/NPL/
+#
+# Software distributed under the NPL is distributed on an "AS IS" basis,
+# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
+# for the specific language governing rights and limitations under the
+# NPL.
+#
+# The Initial Developer of this code under the NPL is Netscape
+# Communications Corporation.  Portions created by Netscape are
+# Copyright (C) 1998 Netscape Communications Corporation.  All Rights
+# Reserved.
+
+DEPTH=..\..\..\.. 
+
+EXPORTS =				\
+	nsIPopupSetFrame.h	\
+    $(NULL)
+
+MODULE=raptor 
+
+include <$(DEPTH)\config\rules.mak>
diff --git a/layout/xul/base/public/nsIPopupSetFrame.h b/layout/xul/base/public/nsIPopupSetFrame.h
new file mode 100644
index 00000000000..3095e9af2e3
--- /dev/null
+++ b/layout/xul/base/public/nsIPopupSetFrame.h
@@ -0,0 +1,44 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "License"); you may not use this file except in
+ * compliance with the License.  You may obtain a copy of the License at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * The Original Code is Mozilla Communicator client code.
+ *
+ * The Initial Developer of the Original Code is Netscape Communications
+ * Corporation.  Portions created by Netscape are Copyright (C) 1998
+ * Netscape Communications Corporation.  All Rights Reserved.
+ */
+
+#ifndef nsIPopupSetFrame_h___
+#define nsIPopupSetFrame_h___
+
+// {E2D804A1-50CA-11d3-BF87-00105A1B0627}
+#define NS_IPOPUPSETFRAME_IID \
+{ 0xe2d804a1, 0x50ca, 0x11d3, { 0xbf, 0x87, 0x0, 0x10, 0x5a, 0x1b, 0x6, 0x27 } }
+
+class nsIFrame;
+class nsIContent;
+
+#include "nsString.h"
+
+class nsIPopupSetFrame : public nsISupports {
+
+public:
+  static const nsIID& GetIID() { static nsIID iid = NS_IPOPUPSETFRAME_IID; return iid; }
+
+  NS_IMETHOD CreatePopup(nsIFrame* aElementFrame, nsIContent* aPopupContent, 
+                         PRInt32 aXPos, PRInt32 aYPos, 
+                         const nsString& aPopupType, const nsString& anAnchorAlignment,
+                         const nsString& aPopupAlignment) = 0;
+};
+
+#endif
+