diff --git a/actors.ts b/actors.ts
index adcccdf6..b088c2a2 100644
--- a/actors.ts
+++ b/actors.ts
@@ -263,16 +263,9 @@ module J2ME {
       return this.superClass ? this.superClass.isAssignableTo(toClass) : false;
     }
 
-    getClassObject(ctx: Context) {
-      var className = this.className;
-      var classObjects = ctx.runtime.classObjects;
-      var classObject = classObjects[className];
-      if (!classObject) {
-        classObject = util.newObject(CLASSES.java_lang_Class);
-        classObject.vmClass = this;
-        classObjects[className] = classObject;
-      }
-      return classObject;
+    getClassObject(ctx: Context): java.lang.Class {
+      // TODO: Check to make sure that it doesn't matter if this is done eagerly.
+      return runtimeKlass(ctx.runtime, this.klass).classObject;
     }
 
     getField(fieldKey: string) : FieldInfo {
diff --git a/context.ts b/context.ts
index b6677ded..ade72ff9 100644
--- a/context.ts
+++ b/context.ts
@@ -12,7 +12,7 @@ module J2ME {
     frameSets: any [];
     lockTimeout: number;
     lockLevel: number;
-    thread: any;
+    thread: java.lang.Thread;
 
     constructor(public runtime: Runtime) {
       this.frames = [];
@@ -248,7 +248,7 @@ module J2ME {
         window.clearTimeout(this.lockTimeout);
         this.lockTimeout = null;
       }
-      if (obj.lock) {
+      if (obj.__lock__) {
         if (!obj.ready)
           obj.ready = [];
         obj.ready.push(this);
@@ -259,10 +259,10 @@ module J2ME {
       }
     }
 
-    monitorEnter(obj) {
-      var lock = obj.lock;
+    monitorEnter(obj: java.lang.Object) {
+      var lock = obj.__lock__;
       if (!lock) {
-        obj.lock = {thread: this.thread, level: 1};
+        obj.__lock__ = new Lock(this.thread, 1);
         return;
       }
       if (lock.thread === this.thread) {
@@ -273,20 +273,20 @@ module J2ME {
     }
 
     monitorExit(obj) {
-      var lock = obj.lock;
+      var lock = obj.__lock__;
       if (lock.thread !== this.thread)
         this.raiseExceptionAndYield("java/lang/IllegalMonitorStateException");
       if (--lock.level > 0) {
         return;
       }
-      obj.lock = null;
+      obj.__lock__ = null;
       this.unblock(obj, "ready", false, function (ctx) {
         ctx.wakeup(obj);
       });
     }
 
     wait(obj, timeout) {
-      var lock = obj.lock;
+      var lock = obj.__lock__;
       if (timeout < 0)
         this.raiseExceptionAndYield("java/lang/IllegalArgumentException");
       if (!lock || lock.thread !== this.thread)
@@ -311,7 +311,7 @@ module J2ME {
     }
 
     notify(obj, notifyAll) {
-      if (!obj.lock || obj.lock.thread !== this.thread)
+      if (!obj.__lock__ || obj.__lock__.thread !== this.thread)
         this.raiseExceptionAndYield("java/lang/IllegalMonitorStateException");
       this.unblock(obj, "waiting", notifyAll, function (ctx) {
         ctx.wakeup(obj);
diff --git a/jit/jvm.ir.ts b/jit/jvm.ir.ts
index fc9e5da3..7ea4047c 100644
--- a/jit/jvm.ir.ts
+++ b/jit/jvm.ir.ts
@@ -607,7 +607,7 @@ module J2ME.C4.Backend {
 
   var friendlyMangledNames = true;
 
-  export function mangleString(s: string) {
+  export function escapeString(s: string) {
     var invalidChars = "[];/<>()";
     var replaceChars = "abc_defg";
     var result = "";
@@ -625,7 +625,7 @@ module J2ME.C4.Backend {
   export function mangleClassAndMethod(methodInfo: MethodInfo) {
     var name = methodInfo.classInfo.className + methodInfo.name + methodInfo.signature;
     if (friendlyMangledNames) {
-      return mangleString(name);
+      return escapeString(name);
     }
     var hash = hashString(name);
     return StringUtilities.variableLengthEncodeInt32(hash);
@@ -634,7 +634,7 @@ module J2ME.C4.Backend {
   export function mangleMethod(methodInfo: MethodInfo) {
     var name = methodInfo.name + methodInfo.signature;
     if (friendlyMangledNames) {
-      return mangleString(name);
+      return escapeString(name);
     }
     var hash = hashString(name);
     return StringUtilities.variableLengthEncodeInt32(hash);
@@ -645,24 +645,15 @@ module J2ME.C4.Backend {
       return "$AK(" + mangleClass(classInfo.elementClass) + ")";
     } else {
       if (friendlyMangledNames) {
-        return mangleString(classInfo.className);
+        return escapeString(classInfo.className);
       }
       var hash = hashString(classInfo.className);
       return StringUtilities.variableLengthEncodeInt32(hash);
     }
   }
 
-  export function mangleClassAndField(fieldInfo: FieldInfo) {
-    var name = fieldInfo.classInfo.className + fieldInfo.name;
-    if (friendlyMangledNames) {
-      return mangleString(name);
-    }
-    var hash = hashString(name);
-    return StringUtilities.variableLengthEncodeInt32(hash);
-  }
-
   export function mangleField(fieldInfo: FieldInfo) {
-    return mangleString(fieldInfo.name);
+    return "$" + escapeString(fieldInfo.name);
   }
 
   function getRuntimeClass(classInfo: ClassInfo) {
diff --git a/native.js b/native.js
index 0e92bb96..bc9899e7 100644
--- a/native.js
+++ b/native.js
@@ -229,7 +229,7 @@ Native.create("java/lang/Object.notifyAll.()V", function(ctx) {
 });
 
 Native.create("java/lang/Class.invoke_clinit.()V", function(ctx) {
-    var classInfo = this.vmClass;
+    var classInfo = this.runtimeKlass.classInfo;
     var className = classInfo.className;
     var runtime = ctx.runtime;
     if (runtime.initialized[className] || runtime.pending[className])
@@ -256,7 +256,7 @@ Native.create("java/lang/Class.invoke_clinit.()V", function(ctx) {
 });
 
 Native.create("java/lang/Class.init9.()V", function(ctx) {
-    var classInfo = this.vmClass;
+    var classInfo = this.runtimeKlass.classInfo;
     var className = classInfo.className;
     var runtime = ctx.runtime;
     if (runtime.initialized[className])
@@ -266,7 +266,7 @@ Native.create("java/lang/Class.init9.()V", function(ctx) {
 });
 
 Native.create("java/lang/Class.getName.()Ljava/lang/String;", function() {
-    return this.vmClass.className.replace(/\//g, ".");
+    return this.runtimeKlass.classInfo.className.replace(/\//g, ".");
 });
 
 Native.create("java/lang/Class.forName.(Ljava/lang/String;)Ljava/lang/Class;", function(name, ctx) {
@@ -285,7 +285,7 @@ Native.create("java/lang/Class.forName.(Ljava/lang/String;)Ljava/lang/Class;", f
 });
 
 Native.create("java/lang/Class.newInstance.()Ljava/lang/Object;", function(ctx) {
-    var className = this.vmClass.className;
+    var className = this.runtimeKlass.classInfo.className;
     var syntheticMethod = new MethodInfo({
       name: "ClassNewInstanceSynthetic",
       signature: "()Ljava/lang/Object;",
@@ -315,21 +315,21 @@ Native.create("java/lang/Class.newInstance.()Ljava/lang/Object;", function(ctx)
 });
 
 Native.create("java/lang/Class.isInterface.()Z", function() {
-    return ACCESS_FLAGS.isInterface(this.vmClass.access_flags);
+    return ACCESS_FLAGS.isInterface(this.runtimeKlass.classInfo.access_flags);
 });
 
 Native.create("java/lang/Class.isArray.()Z", function() {
-    return !!this.vmClass.isArrayClass;
+    return !!this.runtimeKlass.classInfo.isArrayClass;
 });
 
 Native.create("java/lang/Class.isAssignableFrom.(Ljava/lang/Class;)Z", function(fromClass) {
     if (!fromClass)
         throw new JavaException("java/lang/NullPointerException");
-    return fromClass.vmClass.isAssignableTo(this.vmClass);
+    return fromClass.runtimeKlass.classInfo.isAssignableTo(this.runtimeKlass.classInfo);
 });
 
 Native.create("java/lang/Class.isInstance.(Ljava/lang/Object;)Z", function(obj) {
-    return obj && obj.class.isAssignableTo(this.vmClass);
+    return obj && obj.class.isAssignableTo(this.runtimeKlass.classInfo);
 });
 
 Native.create("java/lang/Float.floatToIntBits.(F)I", (function() {
@@ -551,7 +551,7 @@ Native.create("com/sun/cldc/io/ResourceInputStream.open.(Ljava/lang/String;)Ljav
 });
 
 Override.create("com/sun/cldc/io/ResourceInputStream.available.()I", function() {
-    var handle = this.class.getField("I.fileDecoder.Ljava/lang/Object;").get(this);
+    var handle = this.$fileDecoder;
 
     if (!handle) {
         throw new JavaException("java/io/IOException");
@@ -561,7 +561,7 @@ Override.create("com/sun/cldc/io/ResourceInputStream.available.()I", function()
 });
 
 Override.create("com/sun/cldc/io/ResourceInputStream.read.()I", function() {
-    var handle = this.class.getField("I.fileDecoder.Ljava/lang/Object;").get(this);
+    var handle = this.$fileDecoder;
 
     if (!handle) {
         throw new JavaException("java/io/IOException");
@@ -674,8 +674,8 @@ Native.create("com/sun/midp/links/LinkPortal.getLinks0.([Lcom/sun/midp/links/Lin
     var isolateId = ctx.runtime.isolate.id;
 
     for (var i = 0; i < links[isolateId].length; i++) {
-        var nativePointer = links[isolateId][i].class.getField("I.nativePointer.I").get(links[isolateId][i]);
-        linkArray[i].class.getField("I.nativePointer.I").set(linkArray[i], nativePointer);
+        var nativePointer = links[isolateId][i].$nativePointer;
+        linkArray[i].$nativePointer = nativePointer;
         linkArray[i].sender = links[isolateId][i].sender;
         linkArray[i].receiver = links[isolateId][i].receiver;
     }
@@ -692,7 +692,7 @@ Native.create("com/sun/midp/links/LinkPortal.setLinks0.(I[Lcom/sun/midp/links/Li
 Native.create("com/sun/midp/links/Link.init0.(II)V", function(sender, receiver) {
     this.sender = sender;
     this.receiver = receiver;
-    this.class.getField("I.nativePointer.I").set(this, util.id());
+    this.$nativePointer = util.id();
 });
 
 Native.create("com/sun/midp/links/Link.receive0.(Lcom/sun/midp/links/LinkMessage;Lcom/sun/midp/links/Link;)V", function(linkMessage, link) {
@@ -735,7 +735,7 @@ Native.create("java/io/DataInputStream.bytesToUTF.([B)Ljava/lang/String;", funct
 Native.create("com/sun/cldc/i18n/j2me/UTF_8_Writer.encodeUTF8.([CII)[B", function(cbuf, off, len) {
   var outputArray = [];
 
-  var pendingSurrogate = this.class.getField("I.pendingSurrogate.I").get(this);
+  var pendingSurrogate = this.$pendingSurrogate;
 
   var inputChar = 0;
   var outputSize = 0;
@@ -792,7 +792,7 @@ Native.create("com/sun/cldc/i18n/j2me/UTF_8_Writer.encodeUTF8.([CII)[B", functio
     count++;
   }
 
-  this.class.getField("I.pendingSurrogate.I").set(this, pendingSurrogate);
+  this.$pendingSurrogate = pendingSurrogate;
 
   var totalSize = outputArray.reduce(function(total, cur) {
     return total + cur.length;
@@ -812,7 +812,7 @@ Native.create("com/sun/cldc/i18n/j2me/UTF_8_Writer.sizeOf.([CII)I", function(cbu
   var outputSize = 0;
   var outputCount = 0;
   var count = 0;
-  var localPendingSurrogate = this.class.getField("I.pendingSurrogate.I").get(this);
+  var localPendingSurrogate = this.$pendingSurrogate;
   while (count < length) {
     inputChar = 0xffff & cbuf[offset + count];
     if (0 != localPendingSurrogate) {
diff --git a/runtime.ts b/runtime.ts
index 3c7ea080..519d6c94 100644
--- a/runtime.ts
+++ b/runtime.ts
@@ -151,7 +151,7 @@ module J2ME {
     new (): java.lang.Object;
 
     /**
-     * Array klass of this klass constructed via \arrayKlass\.
+     * Array klass of this klass, constructed via \arrayKlass\.
      */
     arrayKlass: ArrayKlass;
 
@@ -186,12 +186,22 @@ module J2ME {
     /**
      * Java class object. This is only available on runtime klasses.
      */
-    class: java.lang.Class
+    classObject: java.lang.Class;
+
+    /**
+     * Wether this class is a runtime class.
+     */
+    isRuntimeKlass: boolean;
   }
 
   export interface ArrayKlass extends Klass {
     elementKlass: Klass;
+  }
 
+  export class Lock {
+    constructor(public thread: java.lang.Thread, public level: number) {
+      // ...
+    }
   }
 
   export module java.lang {
@@ -206,6 +216,11 @@ module J2ME {
        */
       __hashCode__: number;
 
+      /**
+       * Some objects may have a lock.
+       */
+      __lock__: Lock;
+
       clone(): java.lang.Object;
       equals(obj: java.lang.Object): boolean;
       finalize(): void;
@@ -220,16 +235,27 @@ module J2ME {
     }
 
     export interface Class extends java.lang.Object {
-
+      runtimeKlass: Klass;
     }
 
     export interface String extends java.lang.Object {
 
     }
+
+    export interface Thread extends java.lang.Object {
+
+    }
   }
 
   declare var CLASSES;
 
+  function initializeClassObject(klass: Klass) {
+    assert(klass.isRuntimeKlass, "Can only create class objects for runtime klasses.");
+    assert(!klass.classObject);
+    klass.classObject = <java.lang.Class>newObject(Klasses.java.lang.Class);
+    klass.classObject.runtimeKlass = klass;
+  }
+
   /**
    * Called by compiled code to initialize the klass. Klass initializers are reflected as
    * memoizing getters on the |RuntimeTemplate.prototype|. Once they are first accessed,
@@ -241,9 +267,11 @@ module J2ME {
     Object.defineProperty(RuntimeTemplate.prototype, mangledClassName, {
       configurable: true,
       get: function () {
+        assert(!klass.isRuntimeKlass);
         var runtimeKlass = klass.bind(null);
         runtimeKlass.klass = klass;
-        runtimeKlass.class = new Class(runtimeKlass);
+        runtimeKlass.isRuntimeKlass = true;
+        initializeClassObject(runtimeKlass);
         var classInfo = CLASSES.getClass(className);
         Object.defineProperty(this, mangledClassName, {
           configurable: false,
@@ -261,6 +289,13 @@ module J2ME {
     });
   }
 
+  export function runtimeKlass(runtime: Runtime, klass: Klass): Klass {
+    assert(!klass.isRuntimeKlass);
+    var runtimeKlass = runtime[klass.classInfo.mangledName];
+    assert(runtimeKlass.isRuntimeKlass);
+    return runtimeKlass;
+  }
+
   export function createKlass(classInfo: ClassInfo): Klass {
     if (!classInfo) {
       return null;
@@ -390,11 +425,20 @@ module J2ME {
     return arrayKlass;
   }
 
-  export function toDebugString(object: java.lang.Object): string {
-    if (!object) {
+  export function toDebugString(value: any): string {
+    if (typeof value !== "object") {
+      return String(value);
+    }
+    if (!value) {
       return "null";
     }
-    return "[" + object.klass.classInfo.className + " 0x" + object.__hashCode__.toString(16).toUpperCase() + "]";
+    if (!value.klass) {
+      return "no klass";
+    }
+    if (!value.klass.classInfo) {
+      return value.klass + " no classInfo"
+    }
+    return "[" + value.klass.classInfo.className + " 0x" + value.__hashCode__.toString(16).toUpperCase() + "]";
   }
 }
 
diff --git a/vm.js b/vm.js
index df8f9d80..3e2d51a3 100644
--- a/vm.js
+++ b/vm.js
@@ -18,6 +18,8 @@ VM.trace = function(type, pid, methodInfo, returnVal) {
                    (returnVal ? (" " + returnVal) : "") + "\n";
 }
 
+var traceWriter = new J2ME.IndentingWriter();
+
 VM.execute = function(ctx) {
     var frame = ctx.current();
 
@@ -27,6 +29,13 @@ VM.execute = function(ctx) {
 
     function pushFrame(methodInfo) {
         var caller = frame;
+        if (traceWriter) {
+            var args = stack.slice(stack.length - methodInfo.consumes).map(function (x) {
+                return J2ME.toDebugString(x);
+            }).join(", ")
+            traceWriter.enter(methodInfo.implKey + " " + args);
+        }
+
         frame = ctx.pushFrame(methodInfo);
         stack = frame.stack;
         cp = frame.cp;
@@ -43,6 +52,7 @@ VM.execute = function(ctx) {
     }
 
     function popFrame(consumes) {
+        traceWriter && traceWriter.outdent();
         if (frame.lockObject)
             ctx.monitorExit(frame.lockObject);
         var callee = frame;