diff --git a/src/helma/scripting/rhino/RhinoCore.java b/src/helma/scripting/rhino/RhinoCore.java
index 20e3eaae..87e510e8 100644
--- a/src/helma/scripting/rhino/RhinoCore.java
+++ b/src/helma/scripting/rhino/RhinoCore.java
@@ -27,6 +27,8 @@ import helma.util.CacheMap;
 import helma.util.SystemMap;
 import helma.util.WrappedMap;
 import org.mozilla.javascript.*;
+import org.mozilla.javascript.tools.debugger.Main;
+import org.mozilla.javascript.tools.debugger.ScopeProvider;
 
 import java.io.*;
 import java.text.*;
@@ -35,7 +37,7 @@ import java.util.*;
 /**
  * This is the implementation of ScriptingEnvironment for the Mozilla Rhino EcmaScript interpreter.
  */
-public final class RhinoCore {
+public final class RhinoCore implements ScopeProvider {
     // the application we're running in
     public final Application app;
 
@@ -63,6 +65,8 @@ public final class RhinoCore {
     // Any error that may have been found in global code
     String globalError;
 
+    Main debugger = null;
+
     /**
      *  Create a Rhino evaluator for the given application and request evaluator.
      */
@@ -80,14 +84,24 @@ public final class RhinoCore {
         wrapper.setJavaPrimitiveWrap(false);
         context.setWrapFactory(wrapper);
 
-        int optLevel = 0;
+        // Set up visual debugger if rhino.debug = true
+        if ("true".equals(app.getProperty("rhino.debug"))) {
+            debugger = new Main(app.getName() + " Debugger");
+            debugger.setScopeProvider(this);
+            debugger.pack();
+            debugger.setVisible(true);
+            debugger.contextCreated(context);
+            debugger.contextEntered(context);
+        }
+
+        // Set default optimization level according to whether debugger is on
+        int optLevel = debugger == null ? 0 : -1;
 
         try {
             optLevel = Integer.parseInt(app.getProperty("rhino.optlevel"));
         } catch (Exception ignore) {
         }
 
-        // System.err.println("Setting Rhino optlevel to " + optLevel);
         context.setOptimizationLevel(optLevel);
 
         try {
@@ -131,6 +145,11 @@ public final class RhinoCore {
             throw new RuntimeException(e.getMessage());
         } finally {
             Context.exit();
+
+            if (debugger != null) {
+                debugger.contextExited(context);
+                debugger.contextReleased(context);
+            }
         }
     }
 
diff --git a/src/helma/scripting/rhino/RhinoEngine.java b/src/helma/scripting/rhino/RhinoEngine.java
index 71a46864..9cea9e9c 100644
--- a/src/helma/scripting/rhino/RhinoEngine.java
+++ b/src/helma/scripting/rhino/RhinoEngine.java
@@ -154,13 +154,18 @@ public class RhinoEngine implements ScriptingEngine {
         context.setApplicationClassLoader(app.getClassLoader());
         context.setWrapFactory(core.wrapper);
 
-        boolean trace = "true".equals(app.getProperty("rhino.trace"));
+        // if visual debugger is on let it know we're entering a context
+        if (core.debugger != null) {
+            core.debugger.contextCreated(context);
+            core.debugger.contextEntered(context);
+        }
 
-        if (trace) {
+        if ("true".equals(app.getProperty("rhino.trace"))) {
             context.setDebugger(new Tracer(getResponse()), null);
         }
 
-        int optLevel = 0;
+        // Set default optimization level according to whether debugger is on
+        int optLevel = core.debugger == null ? 0 : -1;
 
         try {
             optLevel = Integer.parseInt(app.getProperty("rhino.optlevel"));
@@ -224,6 +229,12 @@ public class RhinoEngine implements ScriptingEngine {
         core.global.unregisterScope();
         thread = null;
 
+        // if visual debugger is on let it know we're exiting a context
+        if (core.debugger != null) {
+            core.debugger.contextExited(context);
+            core.debugger.contextReleased(context);
+        }
+
         // loop through previous globals and unset them, if necessary.
         if (lastGlobals != null) {
            for (Iterator i=lastGlobals.keySet().iterator(); i.hasNext(); ) {