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diff --git a/watchmaker/framework/src/java/main/org/uncommons/watchmaker/framework/operators/CharArrayCrossover.java b/watchmaker/framework/src/java/main/org/uncommons/watchmaker/framework/operators/CharArrayCrossover.java
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+++ b/watchmaker/framework/src/java/main/org/uncommons/watchmaker/framework/operators/CharArrayCrossover.java
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+//=============================================================================
+// Copyright 2006-2010 Daniel W. Dyer
+//
+// Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//=============================================================================
+package org.uncommons.watchmaker.framework.operators;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+import org.uncommons.maths.number.NumberGenerator;
+import org.uncommons.maths.random.Probability;
+
+/**
+ * Cross-over with a configurable number of points (fixed or random) for
+ * arrays of primitive chars.
+ * @author Daniel Dyer
+ */
+public class CharArrayCrossover extends AbstractCrossover<char[]>
+{
+    /**
+     * Default is single-point cross-over, applied to all parents.
+     */
+    public CharArrayCrossover()
+    {
+        this(1);
+    }
+
+
+    /**
+     * Cross-over with a fixed number of cross-over points.
+     * @param crossoverPoints The constant number of cross-over points
+     * to use for all cross-over operations.
+     */
+    public CharArrayCrossover(int crossoverPoints)
+    {
+        super(crossoverPoints);
+    }
+
+
+    /**
+     * Cross-over with a fixed number of cross-over points.  Cross-over
+     * may or may not be applied to a given pair of parents depending on
+     * the {@code crossoverProbability}.
+     * @param crossoverPoints The constant number of cross-over points
+     * to use for all cross-over operations.
+     * @param crossoverProbability The probability that, once selected,
+     * a pair of parents will be subjected to cross-over rather than
+     * being copied, unchanged, into the output population.
+     */
+    public CharArrayCrossover(int crossoverPoints, Probability crossoverProbability)
+    {
+        super(crossoverPoints, crossoverProbability);
+    }
+
+
+    /**
+     * Cross-over with a variable number of cross-over points.
+     * @param crossoverPointsVariable A random variable that provides a number
+     * of cross-over points for each cross-over operation.
+     */
+    public CharArrayCrossover(NumberGenerator<Integer> crossoverPointsVariable)
+    {
+        super(crossoverPointsVariable);
+    }
+
+
+    /**
+     * Sets up a cross-over implementation that uses a variable number of cross-over
+     * points.  Cross-over is applied to a proportion of selected parent pairs, with
+     * the remainder copied unchanged into the output population.  The size of this
+     * evolved proportion is controlled by the {@code crossoverProbabilityVariable}
+     * parameter.
+     * @param crossoverPointsVariable A variable that provides a (possibly constant,
+     * possibly random) number of cross-over points for each cross-over operation.
+     * @param crossoverProbabilityVariable A variable that controls the probability
+     * that, once selected, a pair of parents will be subjected to cross-over rather
+     * than being copied, unchanged, into the output population.
+     */
+    public CharArrayCrossover(NumberGenerator<Integer> crossoverPointsVariable,
+                              NumberGenerator<Probability> crossoverProbabilityVariable)
+    {
+        super(crossoverPointsVariable, crossoverProbabilityVariable);
+    }
+
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    protected List<char[]> mate(char[] parent1,
+                                char[] parent2,
+                                int numberOfCrossoverPoints,
+                                Random rng)
+    {
+        if (parent1.length != parent2.length)
+        {
+            throw new IllegalArgumentException("Cannot perform cross-over with different length parents.");
+        }
+        char[] offspring1 = new char[parent1.length];
+        System.arraycopy(parent1, 0, offspring1, 0, parent1.length);
+        char[] offspring2 = new char[parent2.length];
+        System.arraycopy(parent2, 0, offspring2, 0, parent2.length);
+        // Apply as many cross-overs as required.
+        char[] temp = new char[parent1.length];
+        for (int i = 0; i < numberOfCrossoverPoints; i++)
+        {
+            // Cross-over index is always greater than zero and less than
+            // the length of the parent so that we always pick a point that
+            // will result in a meaningful cross-over.
+            int crossoverIndex = (1 + rng.nextInt(parent1.length - 1));
+            System.arraycopy(offspring1, 0, temp, 0, crossoverIndex);
+            System.arraycopy(offspring2, 0, offspring1, 0, crossoverIndex);
+            System.arraycopy(temp, 0, offspring2, 0, crossoverIndex);
+        }
+        List<char[]> result = new ArrayList<char[]>(2);
+        result.add(offspring1);
+        result.add(offspring2);
+        return result;
+    }
+}