diff --git a/xpcom/ds/nsISupportsIterators.idl b/xpcom/ds/nsISupportsIterators.idl
new file mode 100644
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+++ b/xpcom/ds/nsISupportsIterators.idl
@@ -0,0 +1,310 @@
+/* -*- 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 1.1 (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.org code.
+ *
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 2000 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Contributor(s): 
+ *   Scott Collins <scc@netscape.com>
+ */
+
+/* nsISupportsIterators.idl --- IDL defining general purpose iterators */
+
+
+#include "nsISupports.idl"
+
+
+  /*
+    ...
+  */
+
+
+  /**
+   * ...
+   */
+[scriptable, uuid(7330650e-1dd2-11b2-a0c2-9ff86ee97bed)]
+interface nsIOutputIterator : nsISupports
+  {
+      /**
+       * Put |anElementToPut| into the underlying container or sequence at the position currently pointed to by this iterator.
+       * The iterator and the underlying container or sequence cooperate to |Release()|
+       * the replaced element, if any and if necessary, and to |AddRef()| the new element.
+       *
+       * The result is undefined if this iterator currently points outside the
+       * useful range of the underlying container or sequence.
+       *
+       * @param anElementToPut the element to place into the underlying container or sequence
+       */
+    void putElement( in nsISupports anElementToPut );
+
+      /**
+       * Advance this iterator to the next position in the underlying container or sequence.
+       */
+    void stepForward();
+  };
+
+  /**
+   * ...
+   */
+[scriptable, uuid(85585e12-1dd2-11b2-a930-f6929058269a)]
+interface nsIInputIterator : nsISupports
+  {
+      /**
+       * Retrieve (and |AddRef()|) the element this iterator currently points to.
+       *
+       * The result is undefined if this iterator currently points outside the
+       * useful range of the underlying container or sequence.
+       *
+       * @result a new reference to the element this iterator currently points to (if any)
+       */
+    nsISupports getElement();
+
+      /**
+       * Advance this iterator to the next position in the underlying container or sequence.
+       */
+    void stepForward();
+
+      /**
+       * Test if |anotherIterator| points to the same position in the underlying container or sequence.
+       *
+       * The result is undefined if |anotherIterator| was not created by or for the same underlying container or sequence.
+       *
+       * @param anotherIterator another iterator to compare against, created by or for the same underlying container or sequence
+       * @result true if |anotherIterator| points to the same position in the underlying container or sequence
+       */
+    boolean isEqualTo( in nsISupports anotherIterator );
+
+      /**
+       * Create a new iterator pointing to the same position in the underlying container or sequence to which this iterator currently points.
+       * The returned iterator is suitable for use in a subsequent call to |isEqualTo()| against this iterator.
+       *
+       * @result a new iterator pointing at the same position in the same underlying container or sequence as this iterator
+       */
+    nsISupports clone();
+  };
+
+  /**
+   * ...
+   */
+[scriptable, uuid(8da01646-1dd2-11b2-98a7-c7009045be7e)]
+interface nsIForwardIterator : nsISupports
+  {
+      /**
+       * Retrieve (and |AddRef()|) the element this iterator currently points to.
+       *
+       * The result is undefined if this iterator currently points outside the
+       * useful range of the underlying container or sequence.
+       *
+       * @result a new reference to the element this iterator currently points to (if any)
+       */
+    nsISupports getElement();
+
+      /**
+       * Put |anElementToPut| into the underlying container or sequence at the position currently pointed to by this iterator.
+       * The iterator and the underlying container or sequence cooperate to |Release()|
+       * the replaced element, if any and if necessary, and to |AddRef()| the new element.
+       *
+       * The result is undefined if this iterator currently points outside the
+       * useful range of the underlying container or sequence.
+       *
+       * @param anElementToPut the element to place into the underlying container or sequence
+       */
+    void putElement( in nsISupports anElementToPut );
+
+      /**
+       * Advance this iterator to the next position in the underlying container or sequence.
+       */
+    void stepForward();
+
+      /**
+       * Test if |anotherIterator| points to the same position in the underlying container or sequence.
+       *
+       * The result is undefined if |anotherIterator| was not created by or for the same underlying container or sequence.
+       *
+       * @param anotherIterator another iterator to compare against, created by or for the same underlying container or sequence
+       * @result true if |anotherIterator| points to the same position in the underlying container or sequence
+       */
+    boolean isEqualTo( in nsISupports anotherIterator );
+
+      /**
+       * Create a new iterator pointing to the same position in the underlying container or sequence to which this iterator currently points.
+       * The returned iterator is suitable for use in a subsequent call to |isEqualTo()| against this iterator.
+       *
+       * @result a new iterator pointing at the same position in the same underlying container or sequence as this iterator
+       */
+    nsISupports clone();
+  };
+
+  /**
+   * ...
+   */
+[scriptable, uuid(948defaa-1dd1-11b2-89f6-8ce81f5ebda9)]
+interface nsIBidirectionalIterator : nsISupports
+  {
+      /**
+       * Retrieve (and |AddRef()|) the element this iterator currently points to.
+       *
+       * The result is undefined if this iterator currently points outside the
+       * useful range of the underlying container or sequence.
+       *
+       * @result a new reference to the element this iterator currently points to (if any)
+       */
+    nsISupports getElement();
+
+      /**
+       * Put |anElementToPut| into the underlying container or sequence at the position currently pointed to by this iterator.
+       * The iterator and the underlying container or sequence cooperate to |Release()|
+       * the replaced element, if any and if necessary, and to |AddRef()| the new element.
+       *
+       * The result is undefined if this iterator currently points outside the
+       * useful range of the underlying container or sequence.
+       *
+       * @param anElementToPut the element to place into the underlying container or sequence
+       */
+    void putElement( in nsISupports anElementToPut );
+
+      /**
+       * Advance this iterator to the next position in the underlying container or sequence.
+       */
+    void stepForward();
+
+      /**
+       * Move this iterator to the previous position in the underlying container or sequence.
+       */
+    void stepBackward();
+
+      /**
+       * Test if |anotherIterator| points to the same position in the underlying container or sequence.
+       *
+       * The result is undefined if |anotherIterator| was not created by or for the same underlying container or sequence.
+       *
+       * @param anotherIterator another iterator to compare against, created by or for the same underlying container or sequence
+       * @result true if |anotherIterator| points to the same position in the underlying container or sequence
+       */
+    boolean isEqualTo( in nsISupports anotherIterator );
+
+      /**
+       * Create a new iterator pointing to the same position in the underlying container or sequence to which this iterator currently points.
+       * The returned iterator is suitable for use in a subsequent call to |isEqualTo()| against this iterator.
+       *
+       * @result a new iterator pointing at the same position in the same underlying container or sequence as this iterator
+       */
+    nsISupports clone();
+  };
+
+  /**
+   * ...
+   */
+[scriptable, uuid(9bd6fdb0-1dd1-11b2-9101-d15375968230)]
+interface nsIRandomAccessIterator : nsISupports
+  {
+      /**
+       * Retrieve (and |AddRef()|) the element this iterator currently points to.
+       *
+       * The result is undefined if this iterator currently points outside the
+       * useful range of the underlying container or sequence.
+       *
+       * @result a new reference to the element this iterator currently points to (if any)
+       */
+    nsISupports getElement();
+
+      /**
+       * Retrieve (and |AddRef()|) an element at some offset from where this iterator currently points.
+       * The offset may be negative.  |getElementAt(0)| is equivalent to |getElement()|.
+       *
+       * The result is undefined if this iterator currently points outside the
+       * useful range of the underlying container or sequence.
+       *
+       * @param anOffset a |0|-based offset from the position to which this iterator currently points
+       * @result a new reference to the indicated element (if any)
+       */
+    nsISupports getElementAt( in PRInt32 anOffset );
+
+      /**
+       * Put |anElementToPut| into the underlying container or sequence at the position currently pointed to by this iterator.
+       * The iterator and the underlying container or sequence cooperate to |Release()|
+       * the replaced element, if any and if necessary, and to |AddRef()| the new element.
+       *
+       * The result is undefined if this iterator currently points outside the
+       * useful range of the underlying container or sequence.
+       *
+       * @param anElementToPut the element to place into the underlying container or sequence
+       */
+    void putElement( in nsISupports anElementToPut );
+
+      /**
+       * Put |anElementToPut| into the underlying container or sequence at the position |anOffset| away from that currently pointed to by this iterator.
+       * The iterator and the underlying container or sequence cooperate to |Release()|
+       * the replaced element, if any and if necessary, and to |AddRef()| the new element.
+       * |putElementAt(0, obj)| is equivalent to |putElement(obj)|.
+       *
+       * The result is undefined if this iterator currently points outside the
+       * useful range of the underlying container or sequence.
+       *
+       * @param anOffset a |0|-based offset from the position to which this iterator currently points
+       * @param anElementToPut the element to place into the underlying container or sequence
+       */
+    void putElementAt( in PRInt32 anOffset, in nsISupports anElementToPut );
+
+      /**
+       * Advance this iterator to the next position in the underlying container or sequence.
+       */
+    void stepForward();
+
+      /**
+       * Move this iterator by |anOffset| positions in the underlying container or sequence.
+       * |anOffset| may be negative.  |stepForwardBy(1)| is equivalent to |stepForward()|.
+       * |stepForwardBy(0)| is a no-op.
+       *
+       * @param anOffset a |0|-based offset from the position to which this iterator currently points
+       */
+    void stepForwardBy( in PRInt32 anOffset );
+
+      /**
+       * Move this iterator to the previous position in the underlying container or sequence.
+       */
+    void stepBackward();
+
+      /**
+       * Move this iterator backwards by |anOffset| positions in the underlying container or sequence.
+       * |anOffset| may be negative.  |stepBackwardBy(1)| is equivalent to |stepBackward()|.
+       * |stepBackwardBy(n)| is equivalent to |stepForwardBy(-n)|.  |stepBackwardBy(0)| is a no-op.
+       *
+       * @param anOffset a |0|-based offset from the position to which this iterator currently points
+       */
+    void stepBackwardBy( in PRInt32 anOffset );
+
+      /**
+       * Test if |anotherIterator| points to the same position in the underlying container or sequence.
+       *
+       * The result is undefined if |anotherIterator| was not created by or for the same underlying container or sequence.
+       *
+       * @param anotherIterator another iterator to compare against, created by or for the same underlying container or sequence
+       * @result true if |anotherIterator| points to the same position in the underlying container or sequence
+       */
+    boolean isEqualTo( in nsISupports anotherIterator );
+
+      /**
+       * Create a new iterator pointing to the same position in the underlying container or sequence to which this iterator currently points.
+       * The returned iterator is suitable for use in a subsequent call to |isEqualTo()| against this iterator.
+       *
+       * @result a new iterator pointing at the same position in the same underlying container or sequence as this iterator
+       */
+    nsISupports clone();
+  };
+
+%{C++
+%}