diff --git a/src/helma/util/SystemMap.java b/src/helma/util/SystemMap.java
index 60580a79..8de12f04 100644
--- a/src/helma/util/SystemMap.java
+++ b/src/helma/util/SystemMap.java
@@ -20,7 +20,9 @@ package helma.util;
 import java.util.*;
 
 /**
- * Map class used internally by Helma.
+ * Map class used internally by Helma. We use this class to be able to
+ *  wrap maps as native objects within a scripting engine rather
+ *  than exposing them through Java reflection. 
  */
 public class SystemMap extends HashMap {
 
diff --git a/src/helma/util/WrappedMap.java b/src/helma/util/WrappedMap.java
index c9a86b0b..c0a96465 100644
--- a/src/helma/util/WrappedMap.java
+++ b/src/helma/util/WrappedMap.java
@@ -22,7 +22,12 @@ import java.util.Collection;
 import java.util.HashMap;
 
 /**
- *  A Map that wraps another map and can be set to read-only.
+ *  A Map that wraps another map. We use this class to be able to
+ *  wrap maps as native objects within a scripting engine rather
+ *  than exposing them through Java reflection.
+ *  Additionally, instances of this class can be set to readonly
+ *  and copy-on-write so that the original map is left unchanged
+ *  if the map contents are modified.
  */
 public class WrappedMap implements Map {