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diff --git a/src/library/scala/collection/mutable/Stack.scala b/src/library/scala/collection/mutable/Stack.scala
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+++ b/src/library/scala/collection/mutable/Stack.scala
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+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2003, LAMP/EPFL                  **
+**  __\ \/ /__/ __ |/ /__/ __ |                                         **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+** $Id$
+\*                                                                      */
+
+package scala.collection.mutable;
+
+
+/** A stack implements a data structure which allows to store and retrieve
+ *  objects in a last-in-first-out (LIFO) fashion.
+ *
+ *  @author  Matthias Zenger
+ *  @version 1.1, 03/05/2004
+ */
+[serializable, cloneable]
+class Stack[A] extends MutableList[A] {
+
+    /** Checks if the stack is empty.
+     *
+     *  @return true, iff there is no element on the stack
+     */
+    def isEmpty: Boolean = (first == null);
+
+    /** Pushes a single element on top of the stack.
+     *
+     *  @param  elem        the element to push onto the stack
+     */
+    def +=(elem: A): Unit = prependElem(elem);
+
+    /** Pushes all elements provided by an <code>Iterable</code> object
+     *  on top of the stack. The elements are pushed in the order they
+     *  are given out by the iterator.
+     *
+     *  @param  iter        an iterable object
+     */
+    def ++=(iter: Iterable[A]): Unit = this ++= iter.elements;
+
+    /** Pushes all elements provided by an iterator
+     *  on top of the stack. The elements are pushed in the order they
+     *  are given out by the iterator.
+     *
+     *  @param  iter        an iterator
+     */
+    def ++=(it: Iterator[A]): Unit = it foreach { e => prependElem(e) };
+
+    /** Pushes a sequence of elements on top of the stack. The first element
+     *  is pushed first, etc.
+     *
+     *  @param  elems       a sequence of elements
+     */
+    def push(elems: A*): Unit = (this ++= elems);
+
+    /** Returns the top element of the stack. This method will not remove
+     *  the element from the stack. An error is signaled if there is no
+     *  element on the stack.
+     *
+     *  @return the top element
+     */
+    def top: A = if (first == null) error("stack empty"); else first.elem;
+
+    /** Removes the top element from the stack.
+     */
+    def pop: A =
+        if (first != null) {
+            val res = first.elem;
+            first = first.next;
+            len = len - 1;
+            res
+        } else
+            error("stack empty");
+
+    /**
+     * Removes all elements from the stack. After this operation completed,
+     * the stack will be empty.
+     */
+    def clear: Unit = reset;
+
+    /** Returns an iterator over all elements on the stack. This iterator
+     *  is stable with respect to state changes in the stack object; i.e.
+     *  such changes will not be reflected in the iterator. The iterator
+     *  issues elements in the order they were inserted into the stack
+     *  (FIFO order).
+     *
+     *  @return an iterator over all stack elements.
+     */
+    override def elements: Iterator[A] = toList.elements;
+
+    /** Creates a list of all stack elements in FIFO order.
+     *
+     *  @return the created list.
+     */
+    override def toList: List[A] = super[MutableList].toList.reverse;
+
+    /** Checks if two stacks are structurally identical.
+     *
+     *  @return true, iff both stacks contain the same sequence of elements.
+     */
+    override def equals(that: Any): Boolean = (
+        that.isInstanceOf[Stack[A]] &&
+        { val other = that.asInstanceOf[Stack[A]];
+          elements.zip(other.elements).forall {
+            case Pair(thiselem, thatelem) => thiselem == thatelem;
+        }}
+    );
+
+    /** The hashCode method always yields an error, since it is not
+     *  safe to use mutable stacks as keys in hash tables.
+     *
+     *  @return never.
+     */
+    override def hashCode(): Int = error("unsuitable as hash key");
+
+    /** Returns a textual representation of a stack as a string.
+     *
+     *  @return the string representation of this stack.
+     */
+    override def toString(): String = toList.mkString("Stack(", ", ", ")");
+
+    /** This method clones the stack.
+     *
+     *  @return  a stack with the same elements.
+     */
+    override def clone(): Stack[A] = {
+        val res = new Stack[A];
+        res ++= this;
+        res
+    }
+}