diff --git a/src/d8.js b/src/d8.js
index 3009037..bf26923 100644
--- a/src/d8.js
+++ b/src/d8.js
@@ -25,11 +25,14 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+"use strict";
+
 String.prototype.startsWith = function (str) {
-  if (str.length > this.length)
+  if (str.length > this.length) {
     return false;
+  }
   return this.substr(0, str.length) == str;
-}
+};
 
 function log10(num) {
   return Math.log(num)/Math.log(10);
@@ -52,8 +55,9 @@
   for (var i = 0; i < parts.length; i++) {
     var part = parts[i];
     var next = current[part];
-    if (!next)
+    if (!next) {
       return [];
+    }
     current = next;
   }
   var result = [];
@@ -63,8 +67,9 @@
     var properties = mirror.properties();
     for (var i = 0; i < properties.length; i++) {
       var name = properties[i].name();
-      if (typeof name === 'string' && name.startsWith(last))
+      if (typeof name === 'string' && name.startsWith(last)) {
         result.push(name);
+      }
     }
     current = ToInspectableObject(current.__proto__);
   }
@@ -73,7 +78,7 @@
 
 
 // Global object holding debugger related constants and state.
-const Debug = {};
+var Debug = {};
 
 
 // Debug events which can occour in the V8 JavaScript engine. These originate
@@ -108,22 +113,24 @@
 
 
 // Current debug state.
-const kNoFrame = -1;
+var kNoFrame = -1;
 Debug.State = {
   currentFrame: kNoFrame,
   displaySourceStartLine: -1,
   displaySourceEndLine: -1,
   currentSourceLine: -1
-}
+};
 var trace_compile = false;  // Tracing all compile events?
 var trace_debug_json = false; // Tracing all debug json packets?
-var last_cmd_line = '';
+var last_cmd = '';
 //var lol_is_enabled;  // Set to true in d8.cc if LIVE_OBJECT_LIST is defined.
 var lol_next_dump_index = 0;
-const kDefaultLolLinesToPrintAtATime = 10;
-const kMaxLolLinesToPrintAtATime = 1000;
+var kDefaultLolLinesToPrintAtATime = 10;
+var kMaxLolLinesToPrintAtATime = 1000;
 var repeat_cmd_line = '';
 var is_running = true;
+// Global variable used to store whether a handle was requested.
+var lookup_handle = null;
 
 // Copied from debug-delay.js.  This is needed below:
 function ScriptTypeFlag(type) {
@@ -150,7 +157,7 @@
 }
 
 function DebugEventDetails(response) {
-  details = {text:'', running:false}
+  var details = {text:'', running:false};
 
   // Get the running state.
   details.running = response.running();
@@ -217,7 +224,7 @@
 
     case 'afterCompile':
       if (trace_compile) {
-        result = 'Source ' + body.script.name + ' compiled:\n'
+        result = 'Source ' + body.script.name + ' compiled:\n';
         var source = body.script.source;
         if (!(source[source.length - 1] == '\n')) {
           result += source;
@@ -237,7 +244,7 @@
   }
 
   return details;
-};
+}
 
 
 function SourceInfo(body) {
@@ -279,7 +286,7 @@
 
   // Return the source line text with the underline beneath.
   return source_text + '\n' + underline;
-};
+}
 
 
 // Converts a text command to a JSON request.
@@ -289,7 +296,7 @@
     print("sending: '" + result + "'");
   }
   return result;
-};
+}
 
 
 function DebugRequest(cmd_line) {
@@ -514,7 +521,7 @@
 
 DebugRequest.prototype.JSONRequest = function() {
   return this.request_;
-}
+};
 
 
 function RequestPacket(command) {
@@ -536,14 +543,14 @@
     json += ',"arguments":';
     // Encode the arguments part.
     if (this.arguments.toJSONProtocol) {
-      json += this.arguments.toJSONProtocol()
+      json += this.arguments.toJSONProtocol();
     } else {
       json += SimpleObjectToJSON_(this.arguments);
     }
   }
   json += '}';
   return json;
-}
+};
 
 
 DebugRequest.prototype.createRequest = function(command) {
@@ -583,7 +590,6 @@
 
 // Create a JSON request for the evaluation command.
 DebugRequest.prototype.makeEvaluateJSONRequest_ = function(expression) {
-  // Global varaible used to store whether a handle was requested.
   lookup_handle = null;
 
   if (lol_is_enabled) {
@@ -1310,7 +1316,7 @@
   }
 
   return request;
-}
+};
 
 
 function extractObjId(args) {
@@ -1499,7 +1505,7 @@
   } else {
     throw new Error('Invalid trace arguments.');
   }
-}
+};
 
 // Handle the help command.
 DebugRequest.prototype.helpCommand_ = function(args) {
@@ -1608,7 +1614,7 @@
   print('');
   print('disconnect|exit|quit       - disconnects and quits the debugger');
   print('help                       - prints this help information');
-}
+};
 
 
 function formatHandleReference_(value) {
@@ -1623,7 +1629,7 @@
 function formatObject_(value, include_properties) {
   var result = '';
   result += formatHandleReference_(value);
-  result += ', type: object'
+  result += ', type: object';
   result += ', constructor ';
   var ctor = value.constructorFunctionValue();
   result += formatHandleReference_(ctor);
@@ -1943,7 +1949,7 @@
 
 // Convert a JSON response to text for display in a text based debugger.
 function DebugResponseDetails(response) {
-  details = {text:'', running:false}
+  var details = { text: '', running: false };
 
   try {
     if (!response.success()) {
@@ -2308,7 +2314,7 @@
   }
 
   return details;
-};
+}
 
 
 /**
@@ -2334,7 +2340,7 @@
  */
 ProtocolPackage.prototype.type = function() {
   return this.packet_.type;
-}
+};
 
 
 /**
@@ -2343,7 +2349,7 @@
  */
 ProtocolPackage.prototype.event = function() {
   return this.packet_.event;
-}
+};
 
 
 /**
@@ -2352,7 +2358,7 @@
  */
 ProtocolPackage.prototype.requestSeq = function() {
   return this.packet_.request_seq;
-}
+};
 
 
 /**
@@ -2361,27 +2367,27 @@
  */
 ProtocolPackage.prototype.running = function() {
   return this.packet_.running ? true : false;
-}
+};
 
 
 ProtocolPackage.prototype.success = function() {
   return this.packet_.success ? true : false;
-}
+};
 
 
 ProtocolPackage.prototype.message = function() {
   return this.packet_.message;
-}
+};
 
 
 ProtocolPackage.prototype.command = function() {
   return this.packet_.command;
-}
+};
 
 
 ProtocolPackage.prototype.body = function() {
   return this.packet_.body;
-}
+};
 
 
 ProtocolPackage.prototype.bodyValue = function(index) {
@@ -2390,12 +2396,12 @@
   } else {
     return new ProtocolValue(this.packet_.body, this);
   }
-}
+};
 
 
 ProtocolPackage.prototype.body = function() {
   return this.packet_.body;
-}
+};
 
 
 ProtocolPackage.prototype.lookup = function(handle) {
@@ -2405,12 +2411,12 @@
   } else {
     return new ProtocolReference(handle);
   }
-}
+};
 
 
 ProtocolPackage.prototype.raw_json = function() {
   return this.raw_json_;
-}
+};
 
 
 function ProtocolValue(value, packet) {
@@ -2425,7 +2431,7 @@
  */
 ProtocolValue.prototype.type = function() {
   return this.value_.type;
-}
+};
 
 
 /**
@@ -2434,7 +2440,7 @@
  */
 ProtocolValue.prototype.field = function(name) {
   return this.value_[name];
-}
+};
 
 
 /**
@@ -2444,7 +2450,7 @@
 ProtocolValue.prototype.isPrimitive = function() {
   return this.isUndefined() || this.isNull() || this.isBoolean() ||
          this.isNumber() || this.isString();
-}
+};
 
 
 /**
@@ -2453,7 +2459,7 @@
  */
 ProtocolValue.prototype.handle = function() {
   return this.value_.handle;
-}
+};
 
 
 /**
@@ -2462,7 +2468,7 @@
  */
 ProtocolValue.prototype.isUndefined = function() {
   return this.value_.type == 'undefined';
-}
+};
 
 
 /**
@@ -2471,7 +2477,7 @@
  */
 ProtocolValue.prototype.isNull = function() {
   return this.value_.type == 'null';
-}
+};
 
 
 /**
@@ -2480,7 +2486,7 @@
  */
 ProtocolValue.prototype.isBoolean = function() {
   return this.value_.type == 'boolean';
-}
+};
 
 
 /**
@@ -2489,7 +2495,7 @@
  */
 ProtocolValue.prototype.isNumber = function() {
   return this.value_.type == 'number';
-}
+};
 
 
 /**
@@ -2498,7 +2504,7 @@
  */
 ProtocolValue.prototype.isString = function() {
   return this.value_.type == 'string';
-}
+};
 
 
 /**
@@ -2508,7 +2514,7 @@
 ProtocolValue.prototype.isObject = function() {
   return this.value_.type == 'object' || this.value_.type == 'function' ||
          this.value_.type == 'error' || this.value_.type == 'regexp';
-}
+};
 
 
 /**
@@ -2518,7 +2524,7 @@
 ProtocolValue.prototype.constructorFunctionValue = function() {
   var ctor = this.value_.constructorFunction;
   return this.packet_.lookup(ctor.ref);
-}
+};
 
 
 /**
@@ -2528,7 +2534,7 @@
 ProtocolValue.prototype.protoObjectValue = function() {
   var proto = this.value_.protoObject;
   return this.packet_.lookup(proto.ref);
-}
+};
 
 
 /**
@@ -2537,7 +2543,7 @@
  */
 ProtocolValue.prototype.propertyCount = function() {
   return this.value_.properties ? this.value_.properties.length : 0;
-}
+};
 
 
 /**
@@ -2547,7 +2553,7 @@
 ProtocolValue.prototype.propertyName = function(index) {
   var property = this.value_.properties[index];
   return property.name;
-}
+};
 
 
 /**
@@ -2562,7 +2568,7 @@
     }
   }
   return null;
-}
+};
 
 
 /**
@@ -2572,7 +2578,7 @@
 ProtocolValue.prototype.propertyValue = function(index) {
   var property = this.value_.properties[index];
   return this.packet_.lookup(property.ref);
-}
+};
 
 
 /**
@@ -2581,12 +2587,12 @@
  */
 ProtocolValue.prototype.value = function() {
   return this.value_.value;
-}
+};
 
 
 ProtocolValue.prototype.valueString = function() {
   return this.value_.text;
-}
+};
 
 
 function ProtocolReference(handle) {
@@ -2596,7 +2602,7 @@
 
 ProtocolReference.prototype.handle = function() {
   return this.handle_;
-}
+};
 
 
 function MakeJSONPair_(name, value) {
@@ -2626,7 +2632,7 @@
 
 // Mapping of some control characters to avoid the \uXXXX syntax for most
 // commonly used control cahracters.
-const ctrlCharMap_ = {
+var ctrlCharMap_ = {
   '\b': '\\b',
   '\t': '\\t',
   '\n': '\\n',
@@ -2638,12 +2644,12 @@
 
 
 // Regular expression testing for ", \ and control characters (0x00 - 0x1F).
-const ctrlCharTest_ = new RegExp('["\\\\\x00-\x1F]');
+var ctrlCharTest_ = new RegExp('["\\\\\x00-\x1F]');
 
 
 // Regular expression matching ", \ and control characters (0x00 - 0x1F)
 // globally.
-const ctrlCharMatch_ = new RegExp('["\\\\\x00-\x1F]', 'g');
+var ctrlCharMatch_ = new RegExp('["\\\\\x00-\x1F]', 'g');
 
 
 /**
@@ -2667,7 +2673,7 @@
         // Convert control character to unicode escape sequence.
         return '\\u00' +
           '0' + // TODO %NumberToRadixString(Math.floor(mapped / 16), 16) +
-          '0' // TODO %NumberToRadixString(mapped % 16, 16);
+          '0'; // TODO %NumberToRadixString(mapped % 16, 16)
       })
     + '"';
   }
@@ -2685,12 +2691,12 @@
  * @return {string} JSON formatted Date value
  */
 function DateToISO8601_(value) {
-  function f(n) {
+  var f = function(n) {
     return n < 10 ? '0' + n : n;
-  }
-  function g(n) {
+  };
+  var g = function(n) {
     return n < 10 ? '00' + n : n < 100 ? '0' + n : n;
-  }
+  };
   return builtins.GetUTCFullYearFrom(value)         + '-' +
           f(builtins.GetUTCMonthFrom(value) + 1)    + '-' +
           f(builtins.GetUTCDateFrom(value))         + 'T' +
@@ -2738,7 +2744,7 @@
           if (property_value === null) {
             property_value_json = 'null';
           } else if (typeof property_value.toJSONProtocol == 'function') {
-            property_value_json = property_value.toJSONProtocol(true)
+            property_value_json = property_value.toJSONProtocol(true);
           } else if (property_value.constructor.name == 'Array'){
             property_value_json = SimpleArrayToJSON_(property_value);
           } else {
@@ -2789,7 +2795,7 @@
     }
     var elem = array[i];
     if (elem.toJSONProtocol) {
-      json += elem.toJSONProtocol(true)
+      json += elem.toJSONProtocol(true);
     } else if (typeof(elem) === 'object')  {
       json += SimpleObjectToJSON_(elem);
     } else if (typeof(elem) === 'boolean')  {