diff --git a/src/forward_list.h b/src/forward_list.h
index c791f36e..cc2053d4 100644
--- a/src/forward_list.h
+++ b/src/forward_list.h
@@ -451,7 +451,7 @@ namespace etl
 
       const_pointer operator &() const
       {
-        return iforward_list::data_cast(p_node)->value;
+        return &(iforward_list::data_cast(p_node)->value);
       }
 
       const_pointer operator ->() const
@@ -980,7 +980,7 @@ namespace etl
               ++p_left;
               --left_size;
             }
-            else if (compare(*p_left, *p_right))
+            else if (!compare(*p_right, *p_left))
             {
               // First node of left is lower or same. The node must come from left.
               p_node = p_left;
diff --git a/src/intrusive_forward_list.h b/src/intrusive_forward_list.h
index 00019df8..552949e7 100644
--- a/src/intrusive_forward_list.h
+++ b/src/intrusive_forward_list.h
@@ -687,7 +687,7 @@ namespace etl
               ++i_left;
               --left_size;
             }
-            else if (compare(*i_left, *i_right))
+            else if (!compare(*i_right, *i_left))
             {
               // First link of left is lower or same. The link must come from left.
               i_link = i_left;
diff --git a/src/intrusive_list.h b/src/intrusive_list.h
index 4d72abe2..ebf56f72 100644
--- a/src/intrusive_list.h
+++ b/src/intrusive_list.h
@@ -702,7 +702,7 @@ namespace etl
               i_node = i_left++;
               --left_size;
             }
-            else if (compare(*i_left, *i_right))
+            else if (!compare(*i_right, *i_left))
             {
               // First node of left is lower or same. The node must come from left.
               i_node = i_left++;
diff --git a/src/list.h b/src/list.h
index a1990aa2..7ac53515 100644
--- a/src/list.h
+++ b/src/list.h
@@ -558,12 +558,12 @@ namespace etl
 
       const_pointer operator &() const
       {
-        return ilist::data_cast(p_node)->value;
+        return &(ilist::data_cast(p_node)->value);
       }
 
-      const data_node_t* operator ->() const
+      const_pointer operator ->() const
       {
-        return p_node;
+        return &(ilist::data_cast(p_node)->value);
       }
 
       friend bool operator == (const const_iterator& lhs, const const_iterator& rhs)
@@ -1186,7 +1186,7 @@ namespace etl
               i_node = i_left++;
               --left_size;
             }
-            else if (compare(*i_left, *i_right))
+            else if (!compare(*i_right, *i_left))
             {
               // First node of left is lower or same. The node must come from left.
               i_node = i_left++;
diff --git a/test/data.h b/test/data.h
index 15c10dd4..ed2ede64 100644
--- a/test/data.h
+++ b/test/data.h
@@ -40,12 +40,14 @@ class TestDataDC
 public:
 
   TestDataDC()
-  : value(T())
+  : value(T()),
+    index(0)
   {
   }
 
-  TestDataDC(const T& value)
-    : value(value)
+  TestDataDC(const T& value, int index = 0)
+    : value(value),
+      index(index)
   {
   }
 
@@ -59,7 +61,8 @@ public:
     return value > other.value;
   }
 
-  T value;
+  T   value;
+  int index;
 };
 
 template <typename T>
@@ -89,8 +92,9 @@ class TestDataNDC
 {
 public:
 
-  TestDataNDC(const T& value)
-    : value(value)
+  TestDataNDC(const T& value, int index = 0)
+    : value(value),
+      index(index)
   {}
 
   bool operator < (const TestDataNDC& other) const
@@ -104,6 +108,7 @@ public:
   }
 
   T value;
+  int index;
 };
 
 template <typename T>
diff --git a/test/test_forward_list.cpp b/test/test_forward_list.cpp
index 2f911aa6..cd733421 100644
--- a/test/test_forward_list.cpp
+++ b/test/test_forward_list.cpp
@@ -38,6 +38,7 @@ SOFTWARE.
 #include <forward_list>
 #include <vector>
 #include <string>
+#include <list>
 
 namespace
 {
@@ -56,6 +57,7 @@ namespace
     typedef std::forward_list<ItemNDC> CompareDataNDC;
     typedef std::vector<ItemNDC> InitialDataNDC;
 
+    InitialDataNDC stable_sort_data;
     InitialDataNDC unsorted_data;
     InitialDataNDC sorted_data;
     InitialDataNDC non_unique_data;
@@ -68,10 +70,11 @@ namespace
     {
       SetupFixture()
       {
-        unsorted_data   = { ItemNDC("1"), ItemNDC("0"), ItemNDC("3"), ItemNDC("2"), ItemNDC("5"), ItemNDC("4"), ItemNDC("7"), ItemNDC("6"), ItemNDC("9"), ItemNDC("8") };
-        sorted_data     = { ItemNDC("0"), ItemNDC("1"), ItemNDC("2"), ItemNDC("3"), ItemNDC("4"), ItemNDC("5"), ItemNDC("6"), ItemNDC("7"), ItemNDC("8"), ItemNDC("9") };
-        non_unique_data = { ItemNDC("0"), ItemNDC("0"), ItemNDC("1"), ItemNDC("1"), ItemNDC("2"), ItemNDC("3"), ItemNDC("3"), ItemNDC("3"), ItemNDC("4"), ItemNDC("5") };
-        small_data      = { ItemNDC("0"), ItemNDC("1"), ItemNDC("2"), ItemNDC("3"), ItemNDC("4"), ItemNDC("5") };
+        stable_sort_data = { ItemNDC("1", 1), ItemNDC("2", 2), ItemNDC("3", 3), ItemNDC("2", 4), ItemNDC("0", 5), ItemNDC("2", 6), ItemNDC("7", 7), ItemNDC("4", 8), ItemNDC("4", 9), ItemNDC("8", 10) };
+        unsorted_data    = { ItemNDC("1"), ItemNDC("0"), ItemNDC("3"), ItemNDC("2"), ItemNDC("5"), ItemNDC("4"), ItemNDC("7"), ItemNDC("6"), ItemNDC("9"), ItemNDC("8") };
+        sorted_data      = { ItemNDC("0"), ItemNDC("1"), ItemNDC("2"), ItemNDC("3"), ItemNDC("4"), ItemNDC("5"), ItemNDC("6"), ItemNDC("7"), ItemNDC("8"), ItemNDC("9") };
+        non_unique_data  = { ItemNDC("0"), ItemNDC("0"), ItemNDC("1"), ItemNDC("1"), ItemNDC("2"), ItemNDC("3"), ItemNDC("3"), ItemNDC("3"), ItemNDC("4"), ItemNDC("5") };
+        small_data       = { ItemNDC("0"), ItemNDC("1"), ItemNDC("2"), ItemNDC("3"), ItemNDC("4"), ItemNDC("5") };
       }
     };
 
@@ -260,7 +263,7 @@ namespace
       data.assign(compare_data.begin(), compare_data.end());
       data.assign(compare_data.begin(), compare_data.end());
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -279,7 +282,7 @@ namespace
       data.assign(INITIAL_SIZE, VALUE);
       data.assign(INITIAL_SIZE, VALUE);
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -316,7 +319,7 @@ namespace
       data.insert_after(i_data, INSERT_VALUE);
       compare_data.insert_after(i_compare_data, INSERT_VALUE);
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -332,7 +335,7 @@ namespace
       data.insert_after(i_data, INSERT_VALUE);
       compare_data.insert_after(i_compare_data, INSERT_VALUE);
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -359,7 +362,7 @@ namespace
       data.insert_after(i_data, 2, INSERT_VALUE);
       compare_data.insert_after(i_compare_data, 2, INSERT_VALUE);
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -375,7 +378,7 @@ namespace
       data.insert_after(i_data, 2, INSERT_VALUE);
       compare_data.insert_after(i_compare_data, 2, INSERT_VALUE);
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -393,7 +396,7 @@ namespace
       compare_data.insert_after(compare_data.before_begin(), test2.begin(), test2.end());
       data.insert_after(data.before_begin(), test2.begin(), test2.end());
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -410,7 +413,7 @@ namespace
       compare_data.insert_after(icd, test2.begin(), test2.end());
       data.insert_after(id, test2.begin(), test2.end());
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -439,7 +442,7 @@ namespace
       CHECK_EQUAL(6U, data.size());
       CHECK_EQUAL(6, std::distance(data.begin(), data.end()));
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -566,7 +569,7 @@ namespace
       i_compare_data = compare_data.erase_after(i_compare_data);
       i_data         = data.erase_after(i_data);
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -575,7 +578,7 @@ namespace
       i_compare_data = compare_data.erase_after(compare_data.begin());
       i_data         = data.erase_after(data.begin());
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -592,7 +595,7 @@ namespace
       //std::advance(i_data, data.size() - 1);
       i_data = data.erase_after(i_data);
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
 
@@ -625,7 +628,7 @@ namespace
 
       CHECK_EQUAL(*i_compare_result, *i_result);
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -649,7 +652,7 @@ namespace
 
       CHECK(i_result == data.end());
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -728,7 +731,7 @@ namespace
       compare_data.unique();
       data.unique();
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -743,7 +746,7 @@ namespace
       compare_data.unique();
       data.unique();
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -758,7 +761,7 @@ namespace
       compare_data.remove(ItemNDC("7"));
       data.remove(ItemNDC("7"));
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -773,7 +776,7 @@ namespace
       compare_data.remove_if(std::bind2nd(std::equal_to<ItemNDC>(), ItemNDC("7")));
       data.remove_if(std::bind2nd(std::equal_to<ItemNDC>(), ItemNDC("7")));
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -791,7 +794,7 @@ namespace
       CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
       CHECK_EQUAL(data.size(), size_t(std::distance(data.begin(), data.end())));
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -819,12 +822,35 @@ namespace
       compare_data.sort();
       data.sort();
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
     }
 
+    //*************************************************************************
+    TEST_FIXTURE(SetupFixture, test_stable_sort)
+    {
+      std::list<ItemNDC> compare_data(stable_sort_data.begin(), stable_sort_data.end());
+      DataNDC data(stable_sort_data.begin(), stable_sort_data.end());
+
+      compare_data.sort();
+      data.sort();
+
+      std::list<ItemNDC>::const_iterator citr = compare_data.begin();
+      DataNDC::const_iterator        ditr = data.begin();
+
+      while (ditr != data.end())
+      {
+        const ItemNDC& v = *ditr;
+
+        CHECK_EQUAL(citr->index, ditr->index);
+
+        ++citr;
+        ++ditr;
+      }
+    }
+
     //*************************************************************************
     TEST_FIXTURE(SetupFixture, test_sort_empty)
     {
@@ -834,7 +860,7 @@ namespace
       compare_data.sort();
       data.sort();
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -865,7 +891,7 @@ namespace
       compare_data.splice_after(i_compare_to_before, compare_data, i_compare_from_before);
       data.move_after(i_from_before, i_to_before);
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -886,7 +912,7 @@ namespace
       compare_data.splice_after(i_compare_to_before, compare_data, i_compare_from_before);
       data.move_after(i_from_before, i_to_before);
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -907,7 +933,7 @@ namespace
       compare_data.splice_after(i_compare_to_before, compare_data, i_compare_from_before);
       data.move_after(i_from_before, i_to_before);
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -928,7 +954,7 @@ namespace
       compare_data.splice_after(i_compare_to_before, compare_data, i_compare_from_before);
       data.move_after(i_from_before, i_to_before);
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
@@ -967,7 +993,7 @@ namespace
       compare_data.splice_after(i_compare_to_before, compare_data, i_compare_first_before, i_compare_last);
       data.move_after(i_first_before, i_last, i_to_before);
 
-      CHECK_EQUAL(std::distance(compare_data.begin(), compare_data.end()), data.size());
+      CHECK_EQUAL(size_t(std::distance(compare_data.begin(), compare_data.end())), data.size());
 
       are_equal = std::equal(data.begin(), data.end(), compare_data.begin());
       CHECK(are_equal);
diff --git a/test/test_intrusive_forward_list.cpp b/test/test_intrusive_forward_list.cpp
index e630b965..587d4e9e 100644
--- a/test/test_intrusive_forward_list.cpp
+++ b/test/test_intrusive_forward_list.cpp
@@ -53,8 +53,8 @@ namespace
   {
   public:
 
-    ItemDCNode(const std::string& text)
-      : data(text)
+    ItemDCNode(const std::string& text, int index = 0)
+      : data(text, index)
     {
     }
 
@@ -66,8 +66,8 @@ namespace
   {
   public:
 
-    ItemNDCNode(const std::string& text)
-      : data(text)
+    ItemNDCNode(const std::string& text, int index = 0)
+      : data(text, index)
     {
     }
 
@@ -127,6 +127,7 @@ namespace
 {
   SUITE(test_forward_list)
   {
+    InitialDataNDC stable_sort_data;
     InitialDataNDC unsorted_data;
     InitialDataNDC sorted_data;
     InitialDataNDC sorted_data2;
@@ -146,12 +147,13 @@ namespace
     {
       SetupFixture()
       {
-        unsorted_data   = { ItemNDCNode("1"), ItemNDCNode("0"), ItemNDCNode("3"), ItemNDCNode("2"), ItemNDCNode("5"), ItemNDCNode("4"), ItemNDCNode("7"), ItemNDCNode("6"), ItemNDCNode("9"), ItemNDCNode("8") };
-        sorted_data     = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5"), ItemNDCNode("6"), ItemNDCNode("7"), ItemNDCNode("8"), ItemNDCNode("9") };
-        sorted_data2    = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5"), ItemNDCNode("6"), ItemNDCNode("7"), ItemNDCNode("8"), ItemNDCNode("9") };
-        non_unique_data = { ItemNDCNode("0"), ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("3"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5") };
-        unique_data     = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5") };
-        small_data      = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5") };
+        stable_sort_data = { ItemNDCNode("1", 1), ItemNDCNode("2", 2), ItemNDCNode("3", 3), ItemNDCNode("2", 4), ItemNDCNode("0", 5), ItemNDCNode("2", 6), ItemNDCNode("7", 7), ItemNDCNode("4", 8), ItemNDCNode("4", 9), ItemNDCNode("8", 10) };
+        unsorted_data    = { ItemNDCNode("1"), ItemNDCNode("0"), ItemNDCNode("3"), ItemNDCNode("2"), ItemNDCNode("5"), ItemNDCNode("4"), ItemNDCNode("7"), ItemNDCNode("6"), ItemNDCNode("9"), ItemNDCNode("8") };
+        sorted_data      = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5"), ItemNDCNode("6"), ItemNDCNode("7"), ItemNDCNode("8"), ItemNDCNode("9") };
+        sorted_data2     = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5"), ItemNDCNode("6"), ItemNDCNode("7"), ItemNDCNode("8"), ItemNDCNode("9") };
+        non_unique_data  = { ItemNDCNode("0"), ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("3"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5") };
+        unique_data      = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5") };
+        small_data       = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5") };
 
         merge_data0 = { ItemNDCNode("1"), ItemNDCNode("1"), ItemNDCNode("3"), ItemNDCNode("3"), ItemNDCNode("5"), ItemNDCNode("7"), ItemNDCNode("8") };
         merge_data1 = { ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("3"), ItemNDCNode("6"), ItemNDCNode("9"), ItemNDCNode("9") };
@@ -743,6 +745,29 @@ namespace
       CHECK(are_equal);
     }
 
+    //*************************************************************************
+    TEST_FIXTURE(SetupFixture, test_stable_sort)
+    {
+      std::list<ItemNDCNode> compare_data(stable_sort_data.begin(), stable_sort_data.end());
+      DataNDC0 data(stable_sort_data.begin(), stable_sort_data.end());
+
+      compare_data.sort();
+      data.sort();
+
+      std::list<ItemNDCNode>::const_iterator citr = compare_data.begin();
+      DataNDC0::const_iterator ditr = data.begin();
+
+      while (ditr != data.end())
+      {
+        const ItemNDC& v = ditr->data;
+
+        CHECK_EQUAL(citr->data.index, ditr->data.index);
+
+        ++citr;
+        ++ditr;
+      }
+    }
+
     //*************************************************************************
     TEST_FIXTURE(SetupFixture, test_sort_compare)
     {
diff --git a/test/test_intrusive_list.cpp b/test/test_intrusive_list.cpp
index 2387da30..b3325f15 100644
--- a/test/test_intrusive_list.cpp
+++ b/test/test_intrusive_list.cpp
@@ -65,8 +65,8 @@ namespace
   {
   public:
 
-    ItemNDCNode(const std::string& text)
-      : data(text)
+    ItemNDCNode(const std::string& text, int index = 0)
+      : data(text, index)
     {
     }
 
@@ -140,6 +140,7 @@ namespace
 {
   SUITE(test_intrusive_list)
   {
+    InitialDataNDC stable_sort_data;
     InitialDataNDC unsorted_data;
     InitialDataNDC sorted_data;
     InitialDataNDC sorted_data2;
@@ -157,12 +158,13 @@ namespace
     {
       SetupFixture()
       {
-        unsorted_data   = { ItemNDCNode("1"), ItemNDCNode("0"), ItemNDCNode("3"), ItemNDCNode("2"), ItemNDCNode("5"), ItemNDCNode("4"), ItemNDCNode("7"), ItemNDCNode("6"), ItemNDCNode("9"), ItemNDCNode("8") };
-        sorted_data     = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5"), ItemNDCNode("6"), ItemNDCNode("7"), ItemNDCNode("8"), ItemNDCNode("9") };
-        sorted_data2    = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5"), ItemNDCNode("6"), ItemNDCNode("7"), ItemNDCNode("8"), ItemNDCNode("9") };
-        non_unique_data = { ItemNDCNode("0"), ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("3"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5") };
-        unique_data     = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5") };
-        small_data      = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5") };
+        stable_sort_data = { ItemNDCNode("1", 1), ItemNDCNode("2", 2), ItemNDCNode("3", 3), ItemNDCNode("2", 4), ItemNDCNode("0", 5), ItemNDCNode("2", 6), ItemNDCNode("7", 7), ItemNDCNode("4", 8), ItemNDCNode("4", 9), ItemNDCNode("8", 10) };
+        unsorted_data    = { ItemNDCNode("1"), ItemNDCNode("0"), ItemNDCNode("3"), ItemNDCNode("2"), ItemNDCNode("5"), ItemNDCNode("4"), ItemNDCNode("7"), ItemNDCNode("6"), ItemNDCNode("9"), ItemNDCNode("8") };
+        sorted_data      = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5"), ItemNDCNode("6"), ItemNDCNode("7"), ItemNDCNode("8"), ItemNDCNode("9") };
+        sorted_data2     = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5"), ItemNDCNode("6"), ItemNDCNode("7"), ItemNDCNode("8"), ItemNDCNode("9") };
+        non_unique_data  = { ItemNDCNode("0"), ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("3"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5") };
+        unique_data      = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5") };
+        small_data       = { ItemNDCNode("0"), ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("4"), ItemNDCNode("5") };
 
         merge_data0 = { ItemNDCNode("1"), ItemNDCNode("1"), ItemNDCNode("3"), ItemNDCNode("3"), ItemNDCNode("5"), ItemNDCNode("7"), ItemNDCNode("8") };
         merge_data1 = { ItemNDCNode("1"), ItemNDCNode("2"), ItemNDCNode("3"), ItemNDCNode("3"), ItemNDCNode("6"), ItemNDCNode("9"), ItemNDCNode("9") };
@@ -787,6 +789,29 @@ namespace
       CHECK(are_equal);
     }
 
+    //*************************************************************************
+    TEST_FIXTURE(SetupFixture, test_stable_sort)
+    {
+      std::list<ItemNDCNode> compare_data(stable_sort_data.begin(), stable_sort_data.end());
+      DataNDC0 data(stable_sort_data.begin(), stable_sort_data.end());
+
+      compare_data.sort();
+      data.sort();
+
+      std::list<ItemNDCNode>::const_iterator citr = compare_data.begin();
+      DataNDC0::const_iterator ditr = data.begin();
+
+      while (ditr != data.end())
+      {
+        const ItemNDC& v = ditr->data;
+
+        CHECK_EQUAL(citr->data.index, ditr->data.index);
+
+        ++citr;
+        ++ditr;
+      }
+    }
+
     //*************************************************************************
     TEST_FIXTURE(SetupFixture, test_sort_compare)
     {
diff --git a/test/test_list.cpp b/test/test_list.cpp
index 96a50288..a39bb24f 100644
--- a/test/test_list.cpp
+++ b/test/test_list.cpp
@@ -55,6 +55,7 @@ namespace
     typedef std::list<ItemNDC>   CompareData;
     typedef std::vector<ItemNDC> InitialData;
 
+    InitialData stable_sort_data;
     InitialData unsorted_data;
     InitialData sorted_data;
     InitialData non_unique_data;
@@ -73,10 +74,11 @@ namespace
     {
       SetupFixture()
       {
-        unsorted_data   = { ItemNDC("1"), ItemNDC("0"), ItemNDC("3"), ItemNDC("2"), ItemNDC("5"), ItemNDC("4"), ItemNDC("7"), ItemNDC("6"), ItemNDC("9"), ItemNDC("8") };
-        sorted_data     = { ItemNDC("0"), ItemNDC("1"), ItemNDC("2"), ItemNDC("3"), ItemNDC("4"), ItemNDC("5"), ItemNDC("6"), ItemNDC("7"), ItemNDC("8"), ItemNDC("9") };
-        non_unique_data = { ItemNDC("0"), ItemNDC("0"), ItemNDC("1"), ItemNDC("1"), ItemNDC("2"), ItemNDC("3"), ItemNDC("3"), ItemNDC("3"), ItemNDC("4"), ItemNDC("5") };
-        small_data      = { ItemNDC("0"), ItemNDC("1"), ItemNDC("2"), ItemNDC("3"), ItemNDC("4"), ItemNDC("5") };
+        stable_sort_data = { ItemNDC("1", 1), ItemNDC("2", 2), ItemNDC("3", 3), ItemNDC("2", 4), ItemNDC("0", 5), ItemNDC("2", 6), ItemNDC("7", 7), ItemNDC("4", 8), ItemNDC("4", 9), ItemNDC("8", 10) };
+        unsorted_data    = { ItemNDC("1"), ItemNDC("0"), ItemNDC("3"), ItemNDC("2"), ItemNDC("5"), ItemNDC("4"), ItemNDC("7"), ItemNDC("6"), ItemNDC("9"), ItemNDC("8") };
+        sorted_data      = { ItemNDC("0"), ItemNDC("1"), ItemNDC("2"), ItemNDC("3"), ItemNDC("4"), ItemNDC("5"), ItemNDC("6"), ItemNDC("7"), ItemNDC("8"), ItemNDC("9") };
+        non_unique_data  = { ItemNDC("0"), ItemNDC("0"), ItemNDC("1"), ItemNDC("1"), ItemNDC("2"), ItemNDC("3"), ItemNDC("3"), ItemNDC("3"), ItemNDC("4"), ItemNDC("5") };
+        small_data       = { ItemNDC("0"), ItemNDC("1"), ItemNDC("2"), ItemNDC("3"), ItemNDC("4"), ItemNDC("5") };
 
         merge_data0 = { ItemNDC("1"), ItemNDC("1"), ItemNDC("3"), ItemNDC("3"), ItemNDC("5"), ItemNDC("7"), ItemNDC("8") };
         merge_data1 = { ItemNDC("1"), ItemNDC("2"), ItemNDC("3"), ItemNDC("3"), ItemNDC("6"), ItemNDC("9"), ItemNDC("9") };
@@ -874,6 +876,27 @@ namespace
       CHECK(are_equal);
     }
 
+    //*************************************************************************
+    TEST_FIXTURE(SetupFixture, test_sort_is_stable)
+    {
+      CompareData compare_data(stable_sort_data.begin(), stable_sort_data.end());
+      DataNDC data(stable_sort_data.begin(), stable_sort_data.end());
+
+      compare_data.sort();
+      data.sort();
+
+      CompareData::const_iterator citr = compare_data.begin();
+      DataNDC::const_iterator     ditr = data.begin();
+
+      while (ditr != data.end())
+      {
+        CHECK_EQUAL(citr->index, ditr->index);
+
+        ++citr;
+        ++ditr;
+      }
+    }
+
     //*************************************************************************
     TEST_FIXTURE(SetupFixture, test_sort_trivial)
     {