diff --git a/lib/fs.js b/lib/fs.js
index 3d37a648a7..e637e03f6d 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -63,7 +63,8 @@ function rethrow() {
     var backtrace = new Error;
     return function(err) {
       if (err) {
-        backtrace.message = err.message;
+        backtrace.stack = err.name + ': ' + err.message +
+                          backtrace.stack.substr(backtrace.name.length);
         err = backtrace;
         throw err;
       }
diff --git a/src/cares_wrap.cc b/src/cares_wrap.cc
index b7ba82870f..fa6302b1b2 100644
--- a/src/cares_wrap.cc
+++ b/src/cares_wrap.cc
@@ -272,7 +272,7 @@ class QueryWrap {
   QueryWrap() {
     HandleScope scope;
 
-    object_ = Persistent<Object>::New(Object::New());
+    object_ = Persistent<Object>::New(node_isolate, Object::New());
   }
 
   virtual ~QueryWrap() {
@@ -280,7 +280,7 @@ class QueryWrap {
 
     object_->Delete(oncomplete_sym);
 
-    object_.Dispose();
+    object_.Dispose(node_isolate);
     object_.Clear();
   }
 
diff --git a/src/fs_event_wrap.cc b/src/fs_event_wrap.cc
index 7e3eb8c529..f85f12c812 100644
--- a/src/fs_event_wrap.cc
+++ b/src/fs_event_wrap.cc
@@ -74,7 +74,8 @@ void FSEventWrap::Initialize(Handle<Object> target) {
   NODE_SET_PROTOTYPE_METHOD(t, "close", Close);
 
   target->Set(String::NewSymbol("FSEvent"),
-              Persistent<FunctionTemplate>::New(t)->GetFunction());
+              Persistent<FunctionTemplate>::New(node_isolate,
+                                                t)->GetFunction());
 }
 
 
@@ -172,7 +173,7 @@ Handle<Value> FSEventWrap::Close(const Arguments& args) {
   // and legal, HandleWrap::Close() deals with them the same way.
   assert(!args.Holder().IsEmpty());
   assert(args.Holder()->InternalFieldCount() > 0);
-  void* ptr = args.Holder()->GetPointerFromInternalField(0);
+  void* ptr = args.Holder()->GetAlignedPointerFromInternalField(0);
   FSEventWrap* wrap = static_cast<FSEventWrap*>(ptr);
 
   if (wrap == NULL || wrap->initialized_ == false) {
diff --git a/src/handle_wrap.cc b/src/handle_wrap.cc
index 3f05c7d81b..99fb6bf853 100644
--- a/src/handle_wrap.cc
+++ b/src/handle_wrap.cc
@@ -84,7 +84,7 @@ Handle<Value> HandleWrap::Close(const Arguments& args) {
   HandleScope scope;
 
   HandleWrap *wrap = static_cast<HandleWrap*>(
-      args.Holder()->GetPointerFromInternalField(0));
+      args.Holder()->GetAlignedPointerFromInternalField(0));
 
   // guard against uninitialized handle or double close
   if (wrap == NULL || wrap->handle__ == NULL) {
@@ -115,8 +115,8 @@ HandleWrap::HandleWrap(Handle<Object> object, uv_handle_t* h) {
   HandleScope scope;
   assert(object_.IsEmpty());
   assert(object->InternalFieldCount() > 0);
-  object_ = v8::Persistent<v8::Object>::New(object);
-  object_->SetPointerInInternalField(0, this);
+  object_ = v8::Persistent<v8::Object>::New(node_isolate, object);
+  object_->SetAlignedPointerInInternalField(0, this);
   ngx_queue_insert_tail(&handle_wrap_queue, &handle_wrap_queue_);
 }
 
@@ -147,8 +147,8 @@ void HandleWrap::OnClose(uv_handle_t* handle) {
     MakeCallback(wrap->object_, close_sym, 0, NULL);
   }
 
-  wrap->object_->SetPointerInInternalField(0, NULL);
-  wrap->object_.Dispose();
+  wrap->object_->SetAlignedPointerInInternalField(0, NULL);
+  wrap->object_.Dispose(node_isolate);
   wrap->object_.Clear();
 
   delete wrap;
diff --git a/src/handle_wrap.h b/src/handle_wrap.h
index dbefc2a114..7c88a61d87 100644
--- a/src/handle_wrap.h
+++ b/src/handle_wrap.h
@@ -50,7 +50,7 @@ namespace node {
   assert(!args.Holder().IsEmpty());                                         \
   assert(args.Holder()->InternalFieldCount() > 0);                          \
   type* wrap = static_cast<type*>(                                          \
-      args.Holder()->GetPointerFromInternalField(0));
+      args.Holder()->GetAlignedPointerFromInternalField(0));
 
 class HandleWrap {
   public:
diff --git a/src/node.cc b/src/node.cc
index e17baec825..a8587deb5a 100644
--- a/src/node.cc
+++ b/src/node.cc
@@ -195,7 +195,7 @@ static void Spin(uv_idle_t* handle, int status) {
       abort();
     }
     Local<Function> cb = cb_v.As<Function>();
-    process_tickFromSpinner = Persistent<Function>::New(cb);
+    process_tickFromSpinner = Persistent<Function>::New(node_isolate, cb);
   }
 
   TryCatch try_catch;
@@ -912,7 +912,7 @@ MakeDomainCallback(const Handle<Object> object,
       abort();
     }
     Local<Function> cb = cb_v.As<Function>();
-    process_tickDomainCallback = Persistent<Function>::New(cb);
+    process_tickDomainCallback = Persistent<Function>::New(node_isolate, cb);
   }
 
   // lazy load domain specific symbols
@@ -1002,7 +1002,7 @@ MakeCallback(const Handle<Object> object,
       abort();
     }
     Local<Function> cb = cb_v.As<Function>();
-    process_tickCallback = Persistent<Function>::New(cb);
+    process_tickCallback = Persistent<Function>::New(node_isolate, cb);
   }
 
   TryCatch try_catch;
@@ -1802,7 +1802,7 @@ v8::Handle<v8::Value> MemoryUsage(const v8::Arguments& args) {
 
   // V8 memory usage
   HeapStatistics v8_heap_stats;
-  V8::GetHeapStatistics(&v8_heap_stats);
+  node_isolate->GetHeapStatistics(&v8_heap_stats);
   info->Set(heap_total_symbol,
             Integer::NewFromUnsigned(v8_heap_stats.total_heap_size()));
   info->Set(heap_used_symbol,
@@ -2021,7 +2021,7 @@ static Handle<Value> Binding(const Arguments& args) {
   node_module_struct* modp;
 
   if (binding_cache.IsEmpty()) {
-    binding_cache = Persistent<Object>::New(Object::New());
+    binding_cache = Persistent<Object>::New(node_isolate, Object::New());
   }
 
   Local<Object> exports;
@@ -2307,7 +2307,8 @@ Handle<Object> SetupProcessObject(int argc, char *argv[]) {
 
   process_template->SetClassName(String::NewSymbol("process"));
 
-  process = Persistent<Object>::New(process_template->GetFunction()->NewInstance());
+  process = Persistent<Object>::New(node_isolate,
+                                process_template->GetFunction()->NewInstance());
 
   process->SetAccessor(String::New("title"),
                        ProcessTitleGetter,
@@ -2317,7 +2318,7 @@ Handle<Object> SetupProcessObject(int argc, char *argv[]) {
   process->Set(String::NewSymbol("version"), String::New(NODE_VERSION));
 
   // process.moduleLoadList
-  module_load_list = Persistent<Array>::New(Array::New());
+  module_load_list = Persistent<Array>::New(node_isolate, Array::New());
   process->Set(String::NewSymbol("moduleLoadList"), module_load_list);
 
   // process.versions
@@ -2984,6 +2985,10 @@ char** Init(int argc, char *argv[]) {
   }
   V8::SetFlagsFromCommandLine(&v8argc, v8argv, false);
 
+  // Fetch a reference to the main isolate, so we have a reference to it
+  // even when we need it to access it from another (debugger) thread.
+  node_isolate = Isolate::GetCurrent();
+
 #ifdef __POSIX__
   // Ignore SIGPIPE
   RegisterSignalHandler(SIGPIPE, SIG_IGN);
@@ -2999,10 +3004,6 @@ char** Init(int argc, char *argv[]) {
 
   V8::SetFatalErrorHandler(node::OnFatalError);
 
-  // Fetch a reference to the main isolate, so we have a reference to it
-  // even when we need it to access it from another (debugger) thread.
-  node_isolate = Isolate::GetCurrent();
-
   // If the --debug flag was specified then initialize the debug thread.
   if (use_debug_agent) {
     EnableDebug(debug_wait_connect);
@@ -3111,7 +3112,7 @@ int Start(int argc, char *argv[]) {
 
   V8::Initialize();
   {
-    Locker locker;
+    Locker locker(node_isolate);
     HandleScope handle_scope;
 
     // Create the one and only Context.
@@ -3137,7 +3138,7 @@ int Start(int argc, char *argv[]) {
     RunAtExit();
 
 #ifndef NDEBUG
-    context.Dispose();
+    context.Dispose(node_isolate);
 #endif
   }
 
diff --git a/src/node.h b/src/node.h
index 5769a7b9ce..d01dc40adc 100644
--- a/src/node.h
+++ b/src/node.h
@@ -86,6 +86,8 @@
 
 namespace node {
 
+extern v8::Isolate* node_isolate;
+
 NODE_EXTERN extern bool no_deprecation;
 
 NODE_EXTERN int Start(int argc, char *argv[]);
@@ -96,7 +98,7 @@ void Load(v8::Handle<v8::Object> process);
 void EmitExit(v8::Handle<v8::Object> process);
 
 #define NODE_PSYMBOL(s) \
-  v8::Persistent<v8::String>::New(v8::String::NewSymbol(s))
+  v8::Persistent<v8::String>::New(node_isolate, v8::String::NewSymbol(s))
 
 /* Converts a unixtime to V8 Date */
 #define NODE_UNIXTIME_V8(t) v8::Date::New(1000*static_cast<double>(t))
@@ -153,7 +155,7 @@ v8::Local<v8::Object> BuildStatsObject(const uv_statbuf_t* s);
 static inline v8::Persistent<v8::Function>* cb_persist(
     const v8::Local<v8::Value> &v) {
   v8::Persistent<v8::Function> *fn = new v8::Persistent<v8::Function>();
-  *fn = v8::Persistent<v8::Function>::New(v8::Local<v8::Function>::Cast(v));
+  *fn = v8::Persistent<v8::Function>::New(node_isolate, v8::Local<v8::Function>::Cast(v));
   return fn;
 }
 
@@ -165,7 +167,7 @@ static inline v8::Persistent<v8::Function>* cb_unwrap(void *data) {
 }
 
 static inline void cb_destroy(v8::Persistent<v8::Function> * cb) {
-  cb->Dispose();
+  cb->Dispose(node_isolate);
   delete cb;
 }
 
diff --git a/src/node_buffer.cc b/src/node_buffer.cc
index 21960f8852..55cf91d1cb 100644
--- a/src/node_buffer.cc
+++ b/src/node_buffer.cc
@@ -187,7 +187,7 @@ Buffer::Buffer(Handle<Object> wrapper, size_t length) : ObjectWrap() {
 
   length_ = 0;
   callback_ = NULL;
-  handle_.SetWrapperClassId(BUFFER_CLASS_ID);
+  handle_.SetWrapperClassId(node_isolate, BUFFER_CLASS_ID);
 
   Replace(NULL, length, NULL, NULL);
 }
@@ -208,7 +208,7 @@ void Buffer::Replace(char *data, size_t length,
     callback_(data_, callback_hint_);
   } else if (length_) {
     delete [] data_;
-    V8::AdjustAmountOfExternalAllocatedMemory(
+    node_isolate->AdjustAmountOfExternalAllocatedMemory(
         -static_cast<intptr_t>(sizeof(Buffer) + length_));
   }
 
@@ -222,7 +222,8 @@ void Buffer::Replace(char *data, size_t length,
     data_ = new char[length_];
     if (data)
       memcpy(data_, data, length_);
-    V8::AdjustAmountOfExternalAllocatedMemory(sizeof(Buffer) + length_);
+    node_isolate->AdjustAmountOfExternalAllocatedMemory(sizeof(Buffer) +
+                                                        length_);
   } else {
     data_ = NULL;
   }
@@ -1039,7 +1040,8 @@ bool Buffer::HasInstance(Handle<Value> val) {
 
 Handle<Value> SetFastBufferConstructor(const Arguments& args) {
   assert(args[0]->IsFunction());
-  fast_buffer_constructor = Persistent<Function>::New(args[0].As<Function>());
+  fast_buffer_constructor = Persistent<Function>::New(node_isolate,
+                                                      args[0].As<Function>());
   return Undefined();
 }
 
@@ -1117,7 +1119,7 @@ void Buffer::Initialize(Handle<Object> target) {
   chars_written_sym = NODE_PSYMBOL("_charsWritten");
 
   Local<FunctionTemplate> t = FunctionTemplate::New(Buffer::New);
-  constructor_template = Persistent<FunctionTemplate>::New(t);
+  constructor_template = Persistent<FunctionTemplate>::New(node_isolate, t);
   constructor_template->InstanceTemplate()->SetInternalFieldCount(1);
   constructor_template->SetClassName(String::NewSymbol("SlowBuffer"));
 
diff --git a/src/node_counters.cc b/src/node_counters.cc
index 3c8d49c00b..c5726842a6 100644
--- a/src/node_counters.cc
+++ b/src/node_counters.cc
@@ -122,7 +122,7 @@ void InitPerfCounters(Handle<Object> target) {
   };
 
   for (int i = 0; i < ARRAY_SIZE(tab); i++) {
-    tab[i].templ = Persistent<FunctionTemplate>::New(
+    tab[i].templ = Persistent<FunctionTemplate>::New(node_isolate,
         FunctionTemplate::New(tab[i].func));
     target->Set(String::NewSymbol(tab[i].name), tab[i].templ->GetFunction());
   }
diff --git a/src/node_crypto.cc b/src/node_crypto.cc
index bc8d6db3b2..ff5848fac7 100644
--- a/src/node_crypto.cc
+++ b/src/node_crypto.cc
@@ -141,7 +141,8 @@ void SecureContext::Initialize(Handle<Object> target) {
   HandleScope scope;
 
   Local<FunctionTemplate> t = FunctionTemplate::New(SecureContext::New);
-  secure_context_constructor = Persistent<FunctionTemplate>::New(t);
+  secure_context_constructor = Persistent<FunctionTemplate>::New(node_isolate,
+                                                                 t);
 
   t->InstanceTemplate()->SetInternalFieldCount(1);
   t->SetClassName(String::NewSymbol("SecureContext"));
@@ -1094,7 +1095,7 @@ int Connection::SelectNextProtoCallback_(SSL *s,
 
   // Release old protocol handler if present
   if (!p->selectedNPNProto_.IsEmpty()) {
-    p->selectedNPNProto_.Dispose();
+    p->selectedNPNProto_.Dispose(node_isolate);
   }
 
   if (p->npnProtos_.IsEmpty()) {
@@ -1104,7 +1105,7 @@ int Connection::SelectNextProtoCallback_(SSL *s,
     *outlen = 8;
 
     // set status unsupported
-    p->selectedNPNProto_ = Persistent<Value>::New(False());
+    p->selectedNPNProto_ = Persistent<Value>::New(node_isolate, False());
 
     return SSL_TLSEXT_ERR_OK;
   }
@@ -1117,15 +1118,15 @@ int Connection::SelectNextProtoCallback_(SSL *s,
 
   switch (status) {
     case OPENSSL_NPN_UNSUPPORTED:
-      p->selectedNPNProto_ = Persistent<Value>::New(Null());
+      p->selectedNPNProto_ = Persistent<Value>::New(node_isolate, Null());
       break;
     case OPENSSL_NPN_NEGOTIATED:
-      p->selectedNPNProto_ = Persistent<Value>::New(String::New(
+      p->selectedNPNProto_ = Persistent<Value>::New(node_isolate, String::New(
                                  reinterpret_cast<const char*>(*out), *outlen
                              ));
       break;
     case OPENSSL_NPN_NO_OVERLAP:
-      p->selectedNPNProto_ = Persistent<Value>::New(False());
+      p->selectedNPNProto_ = Persistent<Value>::New(node_isolate, False());
       break;
     default:
       break;
@@ -1145,14 +1146,15 @@ int Connection::SelectSNIContextCallback_(SSL *s, int *ad, void* arg) {
 
   if (servername) {
     if (!p->servername_.IsEmpty()) {
-      p->servername_.Dispose();
+      p->servername_.Dispose(node_isolate);
     }
-    p->servername_ = Persistent<String>::New(String::New(servername));
+    p->servername_ = Persistent<String>::New(node_isolate,
+                                             String::New(servername));
 
     // Call the SNI callback and use its return value as context
     if (!p->sniObject_.IsEmpty()) {
       if (!p->sniContext_.IsEmpty()) {
-        p->sniContext_.Dispose();
+        p->sniContext_.Dispose(node_isolate);
       }
 
       // Get callback init args
@@ -1166,7 +1168,7 @@ int Connection::SelectSNIContextCallback_(SSL *s, int *ad, void* arg) {
 
       // If ret is SecureContext
       if (secure_context_constructor->HasInstance(ret)) {
-        p->sniContext_ = Persistent<Value>::New(ret);
+        p->sniContext_ = Persistent<Value>::New(node_isolate, ret);
         SecureContext *sc = ObjectWrap::Unwrap<SecureContext>(
                                 Local<Object>::Cast(ret));
         SSL_set_SSL_CTX(s, sc->ctx_);
@@ -1993,9 +1995,9 @@ Handle<Value> Connection::SetNPNProtocols(const Arguments& args) {
 
   // Release old handle
   if (!ss->npnProtos_.IsEmpty()) {
-    ss->npnProtos_.Dispose();
+    ss->npnProtos_.Dispose(node_isolate);
   }
-  ss->npnProtos_ = Persistent<Object>::New(args[0]->ToObject());
+  ss->npnProtos_ = Persistent<Object>::New(node_isolate, args[0]->ToObject());
 
   return True();
 };
@@ -2026,9 +2028,9 @@ Handle<Value> Connection::SetSNICallback(const Arguments& args) {
 
   // Release old handle
   if (!ss->sniObject_.IsEmpty()) {
-    ss->sniObject_.Dispose();
+    ss->sniObject_.Dispose(node_isolate);
   }
-  ss->sniObject_ = Persistent<Object>::New(Object::New());
+  ss->sniObject_ = Persistent<Object>::New(node_isolate, Object::New());
   ss->sniObject_->Set(String::New("onselect"), args[0]);
 
   return True();
@@ -3294,7 +3296,7 @@ void EIO_PBKDF2After(uv_work_t* work_req, int status) {
   Persistent<Object> obj = req->obj;
   EIO_PBKDF2After(req, argv);
   MakeCallback(obj, "ondone", ARRAY_SIZE(argv), argv);
-  obj.Dispose();
+  obj.Dispose(node_isolate);
 }
 
 
@@ -3372,7 +3374,7 @@ Handle<Value> PBKDF2(const Arguments& args) {
   req->keylen = keylen;
 
   if (args[4]->IsFunction()) {
-    req->obj = Persistent<Object>::New(Object::New());
+    req->obj = Persistent<Object>::New(node_isolate, Object::New());
     req->obj->Set(String::New("ondone"), args[4]);
     uv_queue_work(uv_default_loop(),
                   &req->work_req,
@@ -3406,7 +3408,7 @@ struct RandomBytesRequest {
 
 RandomBytesRequest::~RandomBytesRequest() {
   if (obj_.IsEmpty()) return;
-  obj_.Dispose();
+  obj_.Dispose(node_isolate);
   obj_.Clear();
 }
 
@@ -3492,7 +3494,7 @@ Handle<Value> RandomBytes(const Arguments& args) {
   req->size_ = size;
 
   if (args[1]->IsFunction()) {
-    req->obj_ = Persistent<Object>::New(Object::New());
+    req->obj_ = Persistent<Object>::New(node_isolate, Object::New());
     req->obj_->Set(String::New("ondone"), args[1]);
 
     uv_queue_work(uv_default_loop(),
diff --git a/src/node_crypto.h b/src/node_crypto.h
index 825823e854..0ceb1f69c9 100644
--- a/src/node_crypto.h
+++ b/src/node_crypto.h
@@ -249,14 +249,14 @@ class Connection : ObjectWrap {
     }
 
 #ifdef OPENSSL_NPN_NEGOTIATED
-    if (!npnProtos_.IsEmpty()) npnProtos_.Dispose();
-    if (!selectedNPNProto_.IsEmpty()) selectedNPNProto_.Dispose();
+    if (!npnProtos_.IsEmpty()) npnProtos_.Dispose(node_isolate);
+    if (!selectedNPNProto_.IsEmpty()) selectedNPNProto_.Dispose(node_isolate);
 #endif
 
 #ifdef SSL_CTRL_SET_TLSEXT_SERVERNAME_CB
-   if (!sniObject_.IsEmpty()) sniObject_.Dispose();
-   if (!sniContext_.IsEmpty()) sniContext_.Dispose();
-   if (!servername_.IsEmpty()) servername_.Dispose();
+   if (!sniObject_.IsEmpty()) sniObject_.Dispose(node_isolate);
+   if (!sniContext_.IsEmpty()) sniContext_.Dispose(node_isolate);
+   if (!servername_.IsEmpty()) servername_.Dispose(node_isolate);
 #endif
   }
 
diff --git a/src/node_dtrace.cc b/src/node_dtrace.cc
index df42af2a97..534b3b9670 100644
--- a/src/node_dtrace.cc
+++ b/src/node_dtrace.cc
@@ -373,7 +373,7 @@ void InitDTrace(Handle<Object> target) {
   };
 
   for (unsigned int i = 0; i < ARRAY_SIZE(tab); i++) {
-    tab[i].templ = Persistent<FunctionTemplate>::New(
+    tab[i].templ = Persistent<FunctionTemplate>::New(node_isolate,
         FunctionTemplate::New(tab[i].func));
     target->Set(String::NewSymbol(tab[i].name), tab[i].templ->GetFunction());
   }
diff --git a/src/node_file.cc b/src/node_file.cc
index c4441bd125..52a300a18c 100644
--- a/src/node_file.cc
+++ b/src/node_file.cc
@@ -954,7 +954,8 @@ void InitFs(Handle<Object> target) {
   HandleScope scope;
   // Initialize the stats object
   Local<FunctionTemplate> stat_templ = FunctionTemplate::New();
-  stats_constructor_template = Persistent<FunctionTemplate>::New(stat_templ);
+  stats_constructor_template = Persistent<FunctionTemplate>::New(node_isolate,
+                                                                 stat_templ);
   target->Set(String::NewSymbol("Stats"),
                stats_constructor_template->GetFunction());
   File::Initialize(target);
diff --git a/src/node_internals.h b/src/node_internals.h
index 10b1742fb5..794770874e 100644
--- a/src/node_internals.h
+++ b/src/node_internals.h
@@ -99,7 +99,7 @@ inline static v8::Handle<v8::Value> ThrowRangeError(const char* errmsg) {
   assert(!args.Holder().IsEmpty());                                         \
   assert(args.Holder()->InternalFieldCount() > 0);                          \
   type* wrap = static_cast<type*>(                                          \
-      args.Holder()->GetPointerFromInternalField(0));                \
+      args.Holder()->GetAlignedPointerFromInternalField(0));                \
   if (!wrap) {                                                              \
     fprintf(stderr, #type ": Aborting due to unwrap failure at %s:%d\n",    \
             __FILE__, __LINE__);                                            \
diff --git a/src/node_object_wrap.h b/src/node_object_wrap.h
index c7fa3eb9ba..4f86da3f3a 100644
--- a/src/node_object_wrap.h
+++ b/src/node_object_wrap.h
@@ -37,6 +37,8 @@
 
 namespace node {
 
+extern v8::Isolate* node_isolate;
+
 class NODE_EXTERN ObjectWrap {
  public:
   ObjectWrap ( ) {
@@ -46,10 +48,10 @@ class NODE_EXTERN ObjectWrap {
 
   virtual ~ObjectWrap ( ) {
     if (!handle_.IsEmpty()) {
-      assert(handle_.IsNearDeath());
-      handle_.ClearWeak();
+      assert(handle_.IsNearDeath(node_isolate));
+      handle_.ClearWeak(node_isolate);
       handle_->SetInternalField(0, v8::Undefined());
-      handle_.Dispose();
+      handle_.Dispose(node_isolate);
       handle_.Clear();
     }
   }
@@ -59,7 +61,7 @@ class NODE_EXTERN ObjectWrap {
   static inline T* Unwrap (v8::Handle<v8::Object> handle) {
     assert(!handle.IsEmpty());
     assert(handle->InternalFieldCount() > 0);
-    return static_cast<T*>(handle->GetPointerFromInternalField(0));
+    return static_cast<T*>(handle->GetAlignedPointerFromInternalField(0));
   }
 
 
@@ -69,15 +71,15 @@ class NODE_EXTERN ObjectWrap {
   inline void Wrap (v8::Handle<v8::Object> handle) {
     assert(handle_.IsEmpty());
     assert(handle->InternalFieldCount() > 0);
-    handle_ = v8::Persistent<v8::Object>::New(handle);
-    handle_->SetPointerInInternalField(0, this);
+    handle_ = v8::Persistent<v8::Object>::New(node_isolate, handle);
+    handle_->SetAlignedPointerInInternalField(0, this);
     MakeWeak();
   }
 
 
   inline void MakeWeak (void) {
-    handle_.MakeWeak(this, WeakCallback);
-    handle_.MarkIndependent();
+    handle_.MakeWeak(node_isolate, this, WeakCallback);
+    handle_.MarkIndependent(node_isolate);
   }
 
   /* Ref() marks the object as being attached to an event loop.
@@ -87,7 +89,7 @@ class NODE_EXTERN ObjectWrap {
   virtual void Ref() {
     assert(!handle_.IsEmpty());
     refs_++;
-    handle_.ClearWeak();
+    handle_.ClearWeak(node_isolate);
   }
 
   /* Unref() marks an object as detached from the event loop.  This is its
@@ -101,7 +103,7 @@ class NODE_EXTERN ObjectWrap {
    */
   virtual void Unref() {
     assert(!handle_.IsEmpty());
-    assert(!handle_.IsWeak());
+    assert(!handle_.IsWeak(node_isolate));
     assert(refs_ > 0);
     if (--refs_ == 0) { MakeWeak(); }
   }
@@ -111,13 +113,15 @@ class NODE_EXTERN ObjectWrap {
 
 
  private:
-  static void WeakCallback (v8::Persistent<v8::Value> value, void *data) {
+  static void WeakCallback(v8::Isolate* env,
+                           v8::Persistent<v8::Value> value,
+                           void* data) {
     v8::HandleScope scope;
 
     ObjectWrap *obj = static_cast<ObjectWrap*>(data);
     assert(value == obj->handle_);
     assert(!obj->refs_);
-    assert(value.IsNearDeath());
+    assert(value.IsNearDeath(env));
     delete obj;
   }
 };
diff --git a/src/node_script.cc b/src/node_script.cc
index 15c56122c7..ca7b9404a7 100644
--- a/src/node_script.cc
+++ b/src/node_script.cc
@@ -124,7 +124,8 @@ void CloneObject(Handle<Object> recv,
         })"
       ), String::New("binding:script"))->Run()
     );
-    cloneObjectMethod = Persistent<Function>::New(cloneObjectMethod_);
+    cloneObjectMethod = Persistent<Function>::New(node_isolate,
+                                                  cloneObjectMethod_);
   }
 
   cloneObjectMethod->Call(recv, 2, args);
@@ -135,7 +136,7 @@ void WrappedContext::Initialize(Handle<Object> target) {
   HandleScope scope;
 
   Local<FunctionTemplate> t = FunctionTemplate::New(WrappedContext::New);
-  constructor_template = Persistent<FunctionTemplate>::New(t);
+  constructor_template = Persistent<FunctionTemplate>::New(node_isolate, t);
   constructor_template->InstanceTemplate()->SetInternalFieldCount(1);
   constructor_template->SetClassName(String::NewSymbol("Context"));
 
@@ -165,7 +166,7 @@ WrappedContext::WrappedContext() : ObjectWrap() {
 
 
 WrappedContext::~WrappedContext() {
-  context_.Dispose();
+  context_.Dispose(node_isolate);
 }
 
 
@@ -187,7 +188,7 @@ void WrappedScript::Initialize(Handle<Object> target) {
   HandleScope scope;
 
   Local<FunctionTemplate> t = FunctionTemplate::New(WrappedScript::New);
-  constructor_template = Persistent<FunctionTemplate>::New(t);
+  constructor_template = Persistent<FunctionTemplate>::New(node_isolate, t);
   constructor_template->InstanceTemplate()->SetInternalFieldCount(1);
   // Note: We use 'NodeScript' instead of 'Script' so that we do not
   // conflict with V8's Script class defined in v8/src/messages.js
@@ -247,7 +248,7 @@ Handle<Value> WrappedScript::New(const Arguments& args) {
 
 
 WrappedScript::~WrappedScript() {
-  script_.Dispose();
+  script_.Dispose(node_isolate);
 }
 
 
@@ -364,7 +365,7 @@ Handle<Value> WrappedScript::EvalMachine(const Arguments& args) {
     // that when this function exits the context will be disposed.
     Persistent<Context> tmp = Context::New();
     context = Local<Context>::New(tmp);
-    tmp.Dispose();
+    tmp.Dispose(node_isolate);
 
   } else if (context_flag == userContext) {
     // Use the passed in context
diff --git a/src/node_stat_watcher.cc b/src/node_stat_watcher.cc
index c3f668c086..4eaad499de 100644
--- a/src/node_stat_watcher.cc
+++ b/src/node_stat_watcher.cc
@@ -38,7 +38,7 @@ void StatWatcher::Initialize(Handle<Object> target) {
   HandleScope scope;
 
   Local<FunctionTemplate> t = FunctionTemplate::New(StatWatcher::New);
-  constructor_template = Persistent<FunctionTemplate>::New(t);
+  constructor_template = Persistent<FunctionTemplate>::New(node_isolate, t);
   constructor_template->InstanceTemplate()->SetInternalFieldCount(1);
   constructor_template->SetClassName(String::NewSymbol("StatWatcher"));
 
diff --git a/src/node_zlib.cc b/src/node_zlib.cc
index ebaba6bb11..d15f371b54 100644
--- a/src/node_zlib.cc
+++ b/src/node_zlib.cc
@@ -89,11 +89,11 @@ class ZCtx : public ObjectWrap {
 
     if (mode_ == DEFLATE || mode_ == GZIP || mode_ == DEFLATERAW) {
       (void)deflateEnd(&strm_);
-      V8::AdjustAmountOfExternalAllocatedMemory(-kDeflateContextSize);
+      node_isolate->AdjustAmountOfExternalAllocatedMemory(-kDeflateContextSize);
     } else if (mode_ == INFLATE || mode_ == GUNZIP || mode_ == INFLATERAW ||
                mode_ == UNZIP) {
       (void)inflateEnd(&strm_);
-      V8::AdjustAmountOfExternalAllocatedMemory(-kInflateContextSize);
+      node_isolate->AdjustAmountOfExternalAllocatedMemory(-kInflateContextSize);
     }
     mode_ = NONE;
 
@@ -406,14 +406,16 @@ class ZCtx : public ObjectWrap {
                                  ctx->windowBits_,
                                  ctx->memLevel_,
                                  ctx->strategy_);
-        V8::AdjustAmountOfExternalAllocatedMemory(kDeflateContextSize);
+        node_isolate->
+                    AdjustAmountOfExternalAllocatedMemory(kDeflateContextSize);
         break;
       case INFLATE:
       case GUNZIP:
       case INFLATERAW:
       case UNZIP:
         ctx->err_ = inflateInit2(&ctx->strm_, ctx->windowBits_);
-        V8::AdjustAmountOfExternalAllocatedMemory(kInflateContextSize);
+        node_isolate->
+                    AdjustAmountOfExternalAllocatedMemory(kInflateContextSize);
         break;
       default:
         assert(0 && "wtf?");
diff --git a/src/pipe_wrap.cc b/src/pipe_wrap.cc
index 3952a0799c..6d651b8820 100644
--- a/src/pipe_wrap.cc
+++ b/src/pipe_wrap.cc
@@ -69,7 +69,7 @@ Local<Object> PipeWrap::Instantiate() {
 PipeWrap* PipeWrap::Unwrap(Local<Object> obj) {
   assert(!obj.IsEmpty());
   assert(obj->InternalFieldCount() > 0);
-  return static_cast<PipeWrap*>(obj->GetPointerFromInternalField(0));
+  return static_cast<PipeWrap*>(obj->GetAlignedPointerFromInternalField(0));
 }
 
 
@@ -114,7 +114,7 @@ void PipeWrap::Initialize(Handle<Object> target) {
   NODE_SET_PROTOTYPE_METHOD(t, "setPendingInstances", SetPendingInstances);
 #endif
 
-  pipeConstructor = Persistent<Function>::New(t->GetFunction());
+  pipeConstructor = Persistent<Function>::New(node_isolate, t->GetFunction());
 
   target->Set(String::NewSymbol("Pipe"), pipeConstructor);
 }
@@ -214,7 +214,7 @@ void PipeWrap::OnConnection(uv_stream_t* handle, int status) {
   // Unwrap the client javascript object.
   assert(client_obj->InternalFieldCount() > 0);
   PipeWrap* client_wrap =
-      static_cast<PipeWrap*>(client_obj->GetPointerFromInternalField(0));
+      static_cast<PipeWrap*>(client_obj->GetAlignedPointerFromInternalField(0));
 
   if (uv_accept(handle, (uv_stream_t*)&client_wrap->handle_)) return;
 
diff --git a/src/req_wrap.h b/src/req_wrap.h
index ba56821bbe..1251cea6db 100644
--- a/src/req_wrap.h
+++ b/src/req_wrap.h
@@ -36,7 +36,7 @@ class ReqWrap {
  public:
   ReqWrap() {
     v8::HandleScope scope;
-    object_ = v8::Persistent<v8::Object>::New(v8::Object::New());
+    object_ = v8::Persistent<v8::Object>::New(node_isolate, v8::Object::New());
 
     v8::Local<v8::Value> domain = v8::Context::GetCurrent()
                                   ->Global()
@@ -58,7 +58,7 @@ class ReqWrap {
     // Assert that someone has called Dispatched()
     assert(req_.data == this);
     assert(!object_.IsEmpty());
-    object_.Dispose();
+    object_.Dispose(node_isolate);
     object_.Clear();
   }
 
diff --git a/src/slab_allocator.cc b/src/slab_allocator.cc
index e0d7b13132..6af7215302 100644
--- a/src/slab_allocator.cc
+++ b/src/slab_allocator.cc
@@ -51,9 +51,9 @@ SlabAllocator::SlabAllocator(unsigned int size) {
 SlabAllocator::~SlabAllocator() {
   if (!initialized_) return;
   if (V8::IsDead()) return;
-  slab_sym_.Dispose();
+  slab_sym_.Dispose(node_isolate);
   slab_sym_.Clear();
-  slab_.Dispose();
+  slab_.Dispose(node_isolate);
   slab_.Clear();
 }
 
@@ -65,7 +65,7 @@ void SlabAllocator::Initialize() {
   offset_ = 0;
   last_ptr_ = NULL;
   initialized_ = true;
-  slab_sym_ = Persistent<String>::New(String::New(sym));
+  slab_sym_ = Persistent<String>::New(node_isolate, String::New(sym));
 }
 
 
@@ -94,9 +94,9 @@ char* SlabAllocator::Allocate(Handle<Object> obj, unsigned int size) {
   }
 
   if (slab_.IsEmpty() || offset_ + size > size_) {
-    slab_.Dispose();
+    slab_.Dispose(node_isolate);
     slab_.Clear();
-    slab_ = Persistent<Object>::New(NewSlab(size_));
+    slab_ = Persistent<Object>::New(node_isolate, NewSlab(size_));
     offset_ = 0;
     last_ptr_ = NULL;
   }
diff --git a/src/stream_wrap.cc b/src/stream_wrap.cc
index fb6edbc3a3..50497140b0 100644
--- a/src/stream_wrap.cc
+++ b/src/stream_wrap.cc
@@ -199,7 +199,7 @@ static Local<Object> AcceptHandle(uv_stream_t* pipe) {
     return Local<Object>();
 
   wrap = static_cast<WrapType*>(
-      wrap_obj->GetPointerFromInternalField(0));
+      wrap_obj->GetAlignedPointerFromInternalField(0));
   handle = wrap->UVHandle();
 
   if (uv_accept(pipe, reinterpret_cast<uv_stream_t*>(handle)))
@@ -436,7 +436,7 @@ Handle<Value> StreamWrap::WriteStringImpl(const Arguments& args) {
       Local<Object> send_handle_obj = args[1]->ToObject();
       assert(send_handle_obj->InternalFieldCount() > 0);
       HandleWrap* send_handle_wrap = static_cast<HandleWrap*>(
-          send_handle_obj->GetPointerFromInternalField(0));
+          send_handle_obj->GetAlignedPointerFromInternalField(0));
       send_handle = send_handle_wrap->GetHandle();
 
       // Reference StreamWrap instance to prevent it from being garbage
diff --git a/src/tcp_wrap.cc b/src/tcp_wrap.cc
index 4c55f2eff5..34ee8a0638 100644
--- a/src/tcp_wrap.cc
+++ b/src/tcp_wrap.cc
@@ -118,7 +118,7 @@ void TCPWrap::Initialize(Handle<Object> target) {
   NODE_SET_PROTOTYPE_METHOD(t, "setSimultaneousAccepts", SetSimultaneousAccepts);
 #endif
 
-  tcpConstructor = Persistent<Function>::New(t->GetFunction());
+  tcpConstructor = Persistent<Function>::New(node_isolate, t->GetFunction());
 
   onconnection_sym = NODE_PSYMBOL("onconnection");
   oncomplete_sym = NODE_PSYMBOL("oncomplete");
@@ -130,7 +130,7 @@ void TCPWrap::Initialize(Handle<Object> target) {
 TCPWrap* TCPWrap::Unwrap(Local<Object> obj) {
   assert(!obj.IsEmpty());
   assert(obj->InternalFieldCount() > 0);
-  return static_cast<TCPWrap*>(obj->GetPointerFromInternalField(0));
+  return static_cast<TCPWrap*>(obj->GetAlignedPointerFromInternalField(0));
 }
 
 
@@ -327,7 +327,7 @@ void TCPWrap::OnConnection(uv_stream_t* handle, int status) {
     // Unwrap the client javascript object.
     assert(client_obj->InternalFieldCount() > 0);
     TCPWrap* client_wrap = static_cast<TCPWrap*>(
-        client_obj->GetPointerFromInternalField(0));
+        client_obj->GetAlignedPointerFromInternalField(0));
 
     if (uv_accept(handle, (uv_stream_t*)&client_wrap->handle_)) return;
 
diff --git a/src/tty_wrap.cc b/src/tty_wrap.cc
index 4be53c8e7b..5ad6106c09 100644
--- a/src/tty_wrap.cc
+++ b/src/tty_wrap.cc
@@ -88,7 +88,7 @@ void TTYWrap::Initialize(Handle<Object> target) {
 TTYWrap* TTYWrap::Unwrap(Local<Object> obj) {
   assert(!obj.IsEmpty());
   assert(obj->InternalFieldCount() > 0);
-  return static_cast<TTYWrap*>(obj->GetPointerFromInternalField(0));
+  return static_cast<TTYWrap*>(obj->GetAlignedPointerFromInternalField(0));
 }
 
 
diff --git a/src/udp_wrap.cc b/src/udp_wrap.cc
index 73b722f675..d3e49e0e2e 100644
--- a/src/udp_wrap.cc
+++ b/src/udp_wrap.cc
@@ -123,8 +123,8 @@ void UDPWrap::Initialize(Handle<Object> target) {
   NODE_SET_PROTOTYPE_METHOD(t, "ref", HandleWrap::Ref);
   NODE_SET_PROTOTYPE_METHOD(t, "unref", HandleWrap::Unref);
 
-  constructor = Persistent<Function>::New(
-      Persistent<FunctionTemplate>::New(t)->GetFunction());
+  constructor = Persistent<Function>::New(node_isolate,
+      Persistent<FunctionTemplate>::New(node_isolate, t)->GetFunction());
   target->Set(String::NewSymbol("UDP"), constructor);
 }
 
@@ -427,7 +427,7 @@ void UDPWrap::OnRecv(uv_udp_t* handle,
 UDPWrap* UDPWrap::Unwrap(Local<Object> obj) {
   assert(!obj.IsEmpty());
   assert(obj->InternalFieldCount() > 0);
-  return static_cast<UDPWrap*>(obj->GetPointerFromInternalField(0));
+  return static_cast<UDPWrap*>(obj->GetAlignedPointerFromInternalField(0));
 }
 
 
diff --git a/src/v8_typed_array.cc b/src/v8_typed_array.cc
index 012fb706c1..3eaf19dca8 100644
--- a/src/v8_typed_array.cc
+++ b/src/v8_typed_array.cc
@@ -48,7 +48,7 @@ class ArrayBuffer {
       return ft_cache;
 
     v8::HandleScope scope;
-    ft_cache = v8::Persistent<v8::FunctionTemplate>::New(
+    ft_cache = v8::Persistent<v8::FunctionTemplate>::New(node::node_isolate,
         v8::FunctionTemplate::New(&ArrayBuffer::V8New));
     ft_cache->SetClassName(v8::String::New("ArrayBuffer"));
     v8::Local<v8::ObjectTemplate> instance = ft_cache->InstanceTemplate();
@@ -69,7 +69,9 @@ class ArrayBuffer {
   }
 
  private:
-  static void WeakCallback(v8::Persistent<v8::Value> value, void* data) {
+  static void WeakCallback(v8::Isolate* env,
+                           v8::Persistent<v8::Value> value,
+                           void* data) {
     v8::Object* obj = v8::Object::Cast(*value);
 
     void* ptr = obj->GetIndexedPropertiesExternalArrayData();
@@ -78,10 +80,10 @@ class ArrayBuffer {
     int size =
         obj->GetIndexedPropertiesExternalArrayDataLength() * element_size;
 
-    v8::V8::AdjustAmountOfExternalAllocatedMemory(-size);
+    node::node_isolate->AdjustAmountOfExternalAllocatedMemory(-size);
 
-    value.ClearWeak();
-    value.Dispose();
+    value.ClearWeak(env);
+    value.Dispose(env);
 
     free(ptr);
   }
@@ -108,7 +110,7 @@ class ArrayBuffer {
     if (!buf)
       return ThrowError("Unable to allocate ArrayBuffer.");
 
-    args.This()->SetPointerInInternalField(0, buf);
+    args.This()->SetAlignedPointerInInternalField(0, buf);
 
     args.This()->Set(v8::String::New("byteLength"),
                      v8::Integer::NewFromUnsigned(num_bytes),
@@ -121,11 +123,11 @@ class ArrayBuffer {
     args.This()->SetIndexedPropertiesToExternalArrayData(
         buf, v8::kExternalUnsignedByteArray, num_bytes);
 
-    v8::V8::AdjustAmountOfExternalAllocatedMemory(num_bytes);
+    node::node_isolate->AdjustAmountOfExternalAllocatedMemory(num_bytes);
 
     v8::Persistent<v8::Object> persistent =
-        v8::Persistent<v8::Object>::New(args.This());
-    persistent.MakeWeak(NULL, &ArrayBuffer::WeakCallback);
+        v8::Persistent<v8::Object>::New(node::node_isolate, args.This());
+    persistent.MakeWeak(node::node_isolate, NULL, &ArrayBuffer::WeakCallback);
 
     return args.This();
   }
@@ -159,8 +161,8 @@ class ArrayBuffer {
 
     if (buffer.IsEmpty()) return v8::Undefined();  // constructor failed
 
-    void* src = args.This()->GetPointerFromInternalField(0);
-    void* dest = buffer->GetPointerFromInternalField(0);
+    void* src = args.This()->GetAlignedPointerFromInternalField(0);
+    void* dest = buffer->GetAlignedPointerFromInternalField(0);
     memcpy(dest, static_cast<char*>(src) + begin, slice_length);
 
     return buffer;
@@ -204,7 +206,7 @@ class TypedArray {
       return ft_cache;
 
     v8::HandleScope scope;
-    ft_cache = v8::Persistent<v8::FunctionTemplate>::New(
+    ft_cache = v8::Persistent<v8::FunctionTemplate>::New(node::node_isolate,
         v8::FunctionTemplate::New(&TypedArray<TBytes, TEAType>::V8New));
     ft_cache->SetClassName(v8::String::New(TEANameTrait<TEAType>::name));
     v8::Local<v8::ObjectTemplate> instance = ft_cache->InstanceTemplate();
@@ -298,7 +300,7 @@ class TypedArray {
                  GetFunction()->NewInstance(1, argv);
       if (buffer.IsEmpty()) return v8::Undefined(); // constructor failed
 
-      void* buf = buffer->GetPointerFromInternalField(0);
+      void* buf = buffer->GetAlignedPointerFromInternalField(0);
       args.This()->SetIndexedPropertiesToExternalArrayData(
           buf, TEAType, length);
       // TODO(deanm): check for failure.
@@ -327,7 +329,7 @@ class TypedArray {
                  GetFunction()->NewInstance(1, argv);
       if (buffer.IsEmpty()) return v8::Undefined(); // constructor failed
 
-      void* buf = buffer->GetPointerFromInternalField(0);
+      void* buf = buffer->GetAlignedPointerFromInternalField(0);
       args.This()->SetIndexedPropertiesToExternalArrayData(
           buf, TEAType, length);
       // TODO(deanm): check for failure.
@@ -569,7 +571,7 @@ class DataView {
       return ft_cache;
 
     v8::HandleScope scope;
-    ft_cache = v8::Persistent<v8::FunctionTemplate>::New(
+    ft_cache = v8::Persistent<v8::FunctionTemplate>::New(node::node_isolate,
         v8::FunctionTemplate::New(&DataView::V8New));
     ft_cache->SetClassName(v8::String::New("DataView"));
     v8::Local<v8::ObjectTemplate> instance = ft_cache->InstanceTemplate();
diff --git a/test/message/error_exit.out b/test/message/error_exit.out
index 11ea76fd72..bef1586e08 100644
--- a/test/message/error_exit.out
+++ b/test/message/error_exit.out
@@ -3,7 +3,7 @@ Exiting with code=1
 assert.js:*
   throw new assert.AssertionError({
         ^
-AssertionError: 1 == 2
+AssertionError
     at Object.<anonymous> (*test*message*error_exit.js:*:*)
     at Module._compile (module.js:*:*)
     at Object.Module._extensions..js (module.js:*:*)
diff --git a/test/message/stack_overflow.js b/test/message/stack_overflow.js
index 91974bee1e..0066313084 100644
--- a/test/message/stack_overflow.js
+++ b/test/message/stack_overflow.js
@@ -25,6 +25,8 @@
 var common = require('../common');
 var assert = require('assert');
 
+Error.stackTraceLimit = 0;
+
 common.error('before');
 
 // stack overflow
diff --git a/test/message/stack_overflow.out b/test/message/stack_overflow.out
index 72dc019ff1..4f7b8b132f 100644
--- a/test/message/stack_overflow.out
+++ b/test/message/stack_overflow.out
@@ -1,6 +1,6 @@
 before
 
-*test*message*stack_overflow.js:31
+*test*message*stack_overflow.js:*
 function stackOverflow() {
                       ^
 RangeError: Maximum call stack size exceeded