diff --git a/1_hello_world/node_4.x/binding.gyp b/1_hello_world/node_4.x/binding.gyp
new file mode 100644
index 00000000..39b171f3
--- /dev/null
+++ b/1_hello_world/node_4.x/binding.gyp
@@ -0,0 +1,8 @@
+{
+  "targets": [
+    {
+      "target_name": "hello",
+      "sources": [ "hello.cc" ]
+    }
+  ]
+}
diff --git a/1_hello_world/node_4.x/hello.cc b/1_hello_world/node_4.x/hello.cc
new file mode 100644
index 00000000..2a900535
--- /dev/null
+++ b/1_hello_world/node_4.x/hello.cc
@@ -0,0 +1,24 @@
+// hello.cc
+#include <node.h>
+
+namespace demo {
+
+using v8::FunctionCallbackInfo;
+using v8::Isolate;
+using v8::Local;
+using v8::Object;
+using v8::String;
+using v8::Value;
+
+void Method(const v8::FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+  args.GetReturnValue().Set(String::NewFromUtf8(isolate, "world"));
+}
+
+void Init(Local<Object> exports) {
+  NODE_SET_METHOD(exports, "hello", Method);
+}
+
+NODE_MODULE(hello, Init)
+
+} // namespace demo
diff --git a/1_hello_world/node_4.x/hello.js b/1_hello_world/node_4.x/hello.js
new file mode 100644
index 00000000..00a05a11
--- /dev/null
+++ b/1_hello_world/node_4.x/hello.js
@@ -0,0 +1,3 @@
+const addon = require('bindings')('hello');
+
+console.log(addon.hello()); // 'world'
diff --git a/1_hello_world/node_4.x/package.json b/1_hello_world/node_4.x/package.json
new file mode 100644
index 00000000..be588dd4
--- /dev/null
+++ b/1_hello_world/node_4.x/package.json
@@ -0,0 +1,14 @@
+{
+  "name": "hello_world",
+  "version": "0.0.0",
+  "description": "Node.js Addons Example #1",
+  "main": "hello.js",
+  "private": true,
+  "scripts": {
+    "test": "node hello.js"
+  },
+  "gypfile": true,
+  "dependencies": {
+    "bindings": "~1.2.1"
+  }
+}
diff --git a/2_function_arguments/node_4.x/addon.cc b/2_function_arguments/node_4.x/addon.cc
new file mode 100644
index 00000000..56ef4b2a
--- /dev/null
+++ b/2_function_arguments/node_4.x/addon.cc
@@ -0,0 +1,51 @@
+// addon.cc
+#include <node.h>
+
+namespace demo {
+
+using v8::Exception;
+using v8::FunctionCallbackInfo;
+using v8::Isolate;
+using v8::Local;
+using v8::Number;
+using v8::Object;
+using v8::String;
+using v8::Value;
+
+// This is the implementation of the "add" method
+// Input arguments are passed using the
+// const FunctionCallbackInfo<Value>& args struct
+void Add(const FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+
+  // Check the number of arguments passed.
+  if (args.Length() < 2) {
+    // Throw an Error that is passed back to JavaScript
+    isolate->ThrowException(Exception::TypeError(
+        String::NewFromUtf8(isolate, "Wrong number of arguments")));
+    return;
+  }
+
+  // Check the argument types
+  if (!args[0]->IsNumber() || !args[1]->IsNumber()) {
+    isolate->ThrowException(Exception::TypeError(
+        String::NewFromUtf8(isolate, "Wrong arguments")));
+    return;
+  }
+
+  // Perform the operation
+  double value = args[0]->NumberValue() + args[1]->NumberValue();
+  Local<Number> num = Number::New(isolate, value);
+
+  // Set the return value (using the passed in
+  // FunctionCallbackInfo<Value>&)
+  args.GetReturnValue().Set(num);
+}
+
+void Init(Local<Object> exports) {
+  NODE_SET_METHOD(exports, "add", Add);
+}
+
+NODE_MODULE(addon, Init)
+
+} // namespace demo
diff --git a/2_function_arguments/node_4.x/addon.js b/2_function_arguments/node_4.x/addon.js
new file mode 100644
index 00000000..ffadfedc
--- /dev/null
+++ b/2_function_arguments/node_4.x/addon.js
@@ -0,0 +1,3 @@
+const addon = require('bindings')('addon.node');
+
+console.log('This should be eight:', addon.add(3, 5));
diff --git a/2_function_arguments/node_4.x/binding.gyp b/2_function_arguments/node_4.x/binding.gyp
new file mode 100644
index 00000000..3c79ca84
--- /dev/null
+++ b/2_function_arguments/node_4.x/binding.gyp
@@ -0,0 +1,8 @@
+{
+  "targets": [
+    {
+      "target_name": "addon",
+      "sources": [ "addon.cc" ]
+    }
+  ]
+}
diff --git a/2_function_arguments/node_4.x/package.json b/2_function_arguments/node_4.x/package.json
new file mode 100644
index 00000000..4ca65df5
--- /dev/null
+++ b/2_function_arguments/node_4.x/package.json
@@ -0,0 +1,15 @@
+{
+  "name": "function_arguments",
+  "version": "0.0.0",
+  "description": "Node.js Addons Example #2",
+  "main": "addon.js",
+  "private": true,
+  "dependencies": {
+    "bindings": "~1.2.1",
+    "nan": "~1.3.0"
+  },
+  "scripts": {
+    "test": "node addon.js"
+  },
+  "gypfile": true
+}
diff --git a/3_callbacks/node_4.x/addon.cc b/3_callbacks/node_4.x/addon.cc
new file mode 100644
index 00000000..c78299f2
--- /dev/null
+++ b/3_callbacks/node_4.x/addon.cc
@@ -0,0 +1,32 @@
+// addon.cc
+#include <node.h>
+
+namespace demo {
+
+using v8::Function;
+using v8::FunctionCallbackInfo;
+using v8::Isolate;
+using v8::Local;
+using v8::Null;
+using v8::Object;
+using v8::String;
+using v8::Value;
+
+void RunCallback(const FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+  if (!args[0]->IsFunction()) {
+    return;
+  }
+  Local<Function> cb = Local<Function>::Cast(args[0]);
+  const unsigned argc = 1;
+  Local<Value> argv[argc] = { String::NewFromUtf8(isolate, "hello, world") };
+  cb->Call(Null(isolate), argc, argv);
+}
+
+void Init(Local<Object> exports, Local<Object> module) {
+  NODE_SET_METHOD(module, "exports", RunCallback);
+}
+
+NODE_MODULE(addon, Init)
+
+} // namespace demo
diff --git a/3_callbacks/node_4.x/addon.js b/3_callbacks/node_4.x/addon.js
new file mode 100644
index 00000000..d12d2ff0
--- /dev/null
+++ b/3_callbacks/node_4.x/addon.js
@@ -0,0 +1,6 @@
+const addon = require('bindings')('addon');
+
+addon((msg) => {
+  console.log(msg); // 'hello world'
+});
+addon(); // nothing
diff --git a/3_callbacks/node_4.x/binding.gyp b/3_callbacks/node_4.x/binding.gyp
new file mode 100644
index 00000000..3c79ca84
--- /dev/null
+++ b/3_callbacks/node_4.x/binding.gyp
@@ -0,0 +1,8 @@
+{
+  "targets": [
+    {
+      "target_name": "addon",
+      "sources": [ "addon.cc" ]
+    }
+  ]
+}
diff --git a/3_callbacks/node_4.x/package.json b/3_callbacks/node_4.x/package.json
new file mode 100644
index 00000000..4de7ece7
--- /dev/null
+++ b/3_callbacks/node_4.x/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "callbacks",
+  "version": "0.0.0",
+  "description": "Node.js Addons Example #3",
+  "main": "addon.js",
+  "private": true,
+  "gypfile": true,
+  "dependencies": {
+    "bindings": "~1.2.1"
+  }
+}
diff --git a/4_object_factory/node_4.x/addon.cc b/4_object_factory/node_4.x/addon.cc
new file mode 100644
index 00000000..cbf959da
--- /dev/null
+++ b/4_object_factory/node_4.x/addon.cc
@@ -0,0 +1,37 @@
+// addon.cc
+#include <node.h>
+
+namespace demo {
+
+using v8::Exception;
+using v8::FunctionCallbackInfo;
+using v8::Isolate;
+using v8::Local;
+using v8::Null;
+using v8::Object;
+using v8::String;
+using v8::Value;
+
+void CreateObject(const FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+
+  if (!args[0]->IsString()) {
+    isolate->ThrowException(Exception::TypeError(
+      String::NewFromUtf8(isolate, "Argument must be a string"))
+    );
+    return;
+  }
+
+  Local<Object> obj = Object::New(isolate);
+  obj->Set(String::NewFromUtf8(isolate, "msg"), args[0]->ToString());
+
+  args.GetReturnValue().Set(obj);
+}
+
+void Init(Local<Object> exports, Local<Object> module) {
+  NODE_SET_METHOD(module, "exports", CreateObject);
+}
+
+NODE_MODULE(addon, Init)
+
+} // namespace demo
diff --git a/4_object_factory/node_4.x/addon.js b/4_object_factory/node_4.x/addon.js
new file mode 100644
index 00000000..d9e7cc38
--- /dev/null
+++ b/4_object_factory/node_4.x/addon.js
@@ -0,0 +1,5 @@
+const addon = require('bindings')('addon');
+
+const obj1 = addon('hello');
+const obj2 = addon('world');
+console.log(obj1.msg + ', ' + obj2.msg); // 'hello, world'
diff --git a/4_object_factory/node_4.x/binding.gyp b/4_object_factory/node_4.x/binding.gyp
new file mode 100644
index 00000000..3c79ca84
--- /dev/null
+++ b/4_object_factory/node_4.x/binding.gyp
@@ -0,0 +1,8 @@
+{
+  "targets": [
+    {
+      "target_name": "addon",
+      "sources": [ "addon.cc" ]
+    }
+  ]
+}
diff --git a/4_object_factory/node_4.x/package.json b/4_object_factory/node_4.x/package.json
new file mode 100644
index 00000000..ce8cfceb
--- /dev/null
+++ b/4_object_factory/node_4.x/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "object_factory",
+  "version": "0.0.0",
+  "description": "Node.js Addons Example #4",
+  "main": "addon.js",
+  "private": true,
+  "gypfile": true,
+  "dependencies": {
+    "bindings": "~1.2.1"
+  }
+}
diff --git a/5_function_factory/node_4.x/addon.cc b/5_function_factory/node_4.x/addon.cc
new file mode 100644
index 00000000..e315f284
--- /dev/null
+++ b/5_function_factory/node_4.x/addon.cc
@@ -0,0 +1,37 @@
+#include <node.h>
+
+namespace demo {
+
+using v8::Function;
+using v8::FunctionCallbackInfo;
+using v8::FunctionTemplate;
+using v8::Isolate;
+using v8::Local;
+using v8::Object;
+using v8::String;
+using v8::Value;
+
+void MyFunction(const FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+  args.GetReturnValue().Set(String::NewFromUtf8(isolate, "hello, world"));
+}
+
+void CreateFunction(const FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+
+  Local<FunctionTemplate> tpl = FunctionTemplate::New(isolate, MyFunction);
+  Local<Function> fn = tpl->GetFunction();
+
+  // omit this to make it anonymous
+  fn->SetName(String::NewFromUtf8(isolate, "theFunction"));
+
+  args.GetReturnValue().Set(fn);
+}
+
+void Init(Local<Object> exports, Local<Object> module) {
+  NODE_SET_METHOD(module, "exports", CreateFunction);
+}
+
+NODE_MODULE(addon, Init)
+
+} // namespace demo
diff --git a/5_function_factory/node_4.x/addon.js b/5_function_factory/node_4.x/addon.js
new file mode 100644
index 00000000..9bbdc811
--- /dev/null
+++ b/5_function_factory/node_4.x/addon.js
@@ -0,0 +1,4 @@
+const addon = require('bindings')('addon');
+
+const fn = addon();
+console.log(fn()); // 'hello, world'
diff --git a/5_function_factory/node_4.x/binding.gyp b/5_function_factory/node_4.x/binding.gyp
new file mode 100644
index 00000000..3c79ca84
--- /dev/null
+++ b/5_function_factory/node_4.x/binding.gyp
@@ -0,0 +1,8 @@
+{
+  "targets": [
+    {
+      "target_name": "addon",
+      "sources": [ "addon.cc" ]
+    }
+  ]
+}
diff --git a/5_function_factory/node_4.x/package.json b/5_function_factory/node_4.x/package.json
new file mode 100644
index 00000000..22f06fb0
--- /dev/null
+++ b/5_function_factory/node_4.x/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "function_factory",
+  "version": "0.0.0",
+  "description": "Node.js Addons Example #5",
+  "main": "addon.js",
+  "private": true,
+  "gypfile": true,
+  "dependencies": {
+    "bindings": "~1.2.1"
+  }
+}
diff --git a/6_object_wrap/node_4.x/addon.cc b/6_object_wrap/node_4.x/addon.cc
new file mode 100644
index 00000000..79dbe924
--- /dev/null
+++ b/6_object_wrap/node_4.x/addon.cc
@@ -0,0 +1,15 @@
+// addon.cc
+#include <node.h>
+#include "myobject.h"
+
+namespace demo {
+
+using v8::Local;
+
+void InitAll(Local<Object> exports) {
+  MyObject::Init(exports);
+}
+
+NODE_MODULE(addon, InitAll)
+
+} // namespace demo
diff --git a/6_object_wrap/node_4.x/addon.js b/6_object_wrap/node_4.x/addon.js
new file mode 100644
index 00000000..c685dd58
--- /dev/null
+++ b/6_object_wrap/node_4.x/addon.js
@@ -0,0 +1,6 @@
+const addon = require('bindings')('addon');
+
+const obj = new addon.MyObject(10);
+console.log( obj.plusOne() ); // 11
+console.log( obj.plusOne() ); // 12
+console.log( obj.plusOne() ); // 13
diff --git a/6_object_wrap/node_4.x/binding.gyp b/6_object_wrap/node_4.x/binding.gyp
new file mode 100644
index 00000000..b05e7abc
--- /dev/null
+++ b/6_object_wrap/node_4.x/binding.gyp
@@ -0,0 +1,8 @@
+{
+  "targets": [
+    {
+      "target_name": "addon",
+      "sources": [ "addon.cc", "myobject.cc" ]
+    }
+  ]
+}
diff --git a/6_object_wrap/node_4.x/myobject.cc b/6_object_wrap/node_4.x/myobject.cc
new file mode 100644
index 00000000..5da01109
--- /dev/null
+++ b/6_object_wrap/node_4.x/myobject.cc
@@ -0,0 +1,67 @@
+#include "myobject.h"
+
+namespace demo {
+
+using v8::Function;
+using v8::FunctionCallbackInfo;
+using v8::FunctionTemplate;
+using v8::Isolate;
+using v8::Local;
+using v8::Number;
+using v8::Object;
+using v8::Persistent;
+using v8::String;
+using v8::Value;
+
+Persistent<Function> MyObject::constructor;
+
+MyObject::MyObject(double value) : value_(value) {
+}
+
+MyObject::~MyObject() {
+}
+
+void MyObject::Init(Local<Object> exports) {
+  Isolate* isolate = exports->GetIsolate();
+
+  // Prepare constructor template
+  Local<FunctionTemplate> tpl = FunctionTemplate::New(isolate, New);
+  tpl->SetClassName(String::NewFromUtf8(isolate, "MyObject"));
+  tpl->InstanceTemplate()->SetInternalFieldCount(1);
+
+  // Prototype
+  NODE_SET_PROTOTYPE_METHOD(tpl, "plusOne", PlusOne);
+
+  constructor.Reset(isolate, tpl->GetFunction());
+  exports->Set(String::NewFromUtf8(isolate, "MyObject"),
+               tpl->GetFunction());
+}
+
+void MyObject::New(const FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+
+  if (args.IsConstructCall()) {
+    // Invoked as constructor: `new MyObject(...)`
+    double value = args[0]->IsUndefined() ? 0 : args[0]->NumberValue();
+    MyObject* obj = new MyObject(value);
+    obj->Wrap(args.This());
+    return;
+  } else {
+    // Invoked as plain function `MyObject(...)`, turn into construct call.
+    const int argc = 1;
+    Local<Value> argv[argc] = { args[0] };
+    Local<Function> cons = Local<Function>::New(isolate, constructor);
+    args.GetReturnValue().Set(cons->NewInstance(argc, argv));
+  }
+}
+
+void MyObject::PlusOne(const FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+
+  MyObject* obj = ObjectWrap::Unwrap<MyObject>(args.Holder());
+  obj->value_ += 1;
+
+  args.GetReturnValue().Set(Number::New(isolate, obj->value_));
+}
+
+} // namespace demo
diff --git a/6_object_wrap/node_4.x/myobject.h b/6_object_wrap/node_4.x/myobject.h
new file mode 100644
index 00000000..26e9c3f6
--- /dev/null
+++ b/6_object_wrap/node_4.x/myobject.h
@@ -0,0 +1,32 @@
+#ifndef MYOBJECT_H
+#define MYOBJECT_H
+
+#include <node.h>
+#include <node_object_wrap.h>
+
+namespace demo {
+
+using v8::Function;
+using v8::FunctionCallbackInfo;
+using v8::Local;
+using v8::Object;
+using v8::Persistent;
+using v8::Value;
+
+class MyObject : public node::ObjectWrap {
+ public:
+  static void Init(Local<Object> exports);
+
+ private:
+  explicit MyObject(double value = 0);
+  ~MyObject();
+
+  static void New(const FunctionCallbackInfo<Value>& args);
+  static void PlusOne(const FunctionCallbackInfo<Value>& args);
+  static Persistent<Function> constructor;
+  double value_;
+};
+
+} // namespace demo
+
+#endif
diff --git a/6_object_wrap/node_4.x/package.json b/6_object_wrap/node_4.x/package.json
new file mode 100644
index 00000000..162c5861
--- /dev/null
+++ b/6_object_wrap/node_4.x/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "object_wrap",
+  "version": "0.0.0",
+  "description": "Node.js Addons Example #6",
+  "main": "addon.js",
+  "private": true,
+  "gypfile": true,
+  "dependencies": {
+    "bindings": "~1.2.1"
+  }
+}
diff --git a/7_factory_wrap/node_4.x/addon.cc b/7_factory_wrap/node_4.x/addon.cc
new file mode 100644
index 00000000..719db7db
--- /dev/null
+++ b/7_factory_wrap/node_4.x/addon.cc
@@ -0,0 +1,25 @@
+#include <node.h>
+#include "myobject.h"
+
+namespace demo {
+
+using v8::FunctionCallbackInfo;
+using v8::Isolate;
+using v8::Local;
+using v8::Object;
+using v8::String;
+using v8::Value;
+
+void CreateObject(const FunctionCallbackInfo<Value>& args) {
+  MyObject::NewInstance(args);
+}
+
+void InitAll(Local<Object> exports, Local<Object> module) {
+  MyObject::Init(exports->GetIsolate());
+
+  NODE_SET_METHOD(module, "exports", CreateObject);
+}
+
+NODE_MODULE(addon, InitAll)
+
+} // namespace demo
diff --git a/7_factory_wrap/node_4.x/addon.js b/7_factory_wrap/node_4.x/addon.js
new file mode 100644
index 00000000..0547abe0
--- /dev/null
+++ b/7_factory_wrap/node_4.x/addon.js
@@ -0,0 +1,11 @@
+const createObject = require('bindings')('addon');
+
+const obj = createObject(10);
+console.log( obj.plusOne() ); // 11
+console.log( obj.plusOne() ); // 12
+console.log( obj.plusOne() ); // 13
+
+const obj2 = createObject(20);
+console.log( obj2.plusOne() ); // 21
+console.log( obj2.plusOne() ); // 22
+console.log( obj2.plusOne() ); // 23
diff --git a/7_factory_wrap/node_4.x/binding.gyp b/7_factory_wrap/node_4.x/binding.gyp
new file mode 100644
index 00000000..b05e7abc
--- /dev/null
+++ b/7_factory_wrap/node_4.x/binding.gyp
@@ -0,0 +1,8 @@
+{
+  "targets": [
+    {
+      "target_name": "addon",
+      "sources": [ "addon.cc", "myobject.cc" ]
+    }
+  ]
+}
diff --git a/7_factory_wrap/node_4.x/myobject.cc b/7_factory_wrap/node_4.x/myobject.cc
new file mode 100644
index 00000000..f3f4e712
--- /dev/null
+++ b/7_factory_wrap/node_4.x/myobject.cc
@@ -0,0 +1,75 @@
+#include <node.h>
+#include "myobject.h"
+
+namespace demo {
+
+using v8::Function;
+using v8::FunctionCallbackInfo;
+using v8::FunctionTemplate;
+using v8::Isolate;
+using v8::Local;
+using v8::Number;
+using v8::Object;
+using v8::Persistent;
+using v8::String;
+using v8::Value;
+
+Persistent<Function> MyObject::constructor;
+
+MyObject::MyObject(double value) : value_(value) {
+}
+
+MyObject::~MyObject() {
+}
+
+void MyObject::Init(Isolate* isolate) {
+  // Prepare constructor template
+  Local<FunctionTemplate> tpl = FunctionTemplate::New(isolate, New);
+  tpl->SetClassName(String::NewFromUtf8(isolate, "MyObject"));
+  tpl->InstanceTemplate()->SetInternalFieldCount(1);
+
+  // Prototype
+  NODE_SET_PROTOTYPE_METHOD(tpl, "plusOne", PlusOne);
+
+  constructor.Reset(isolate, tpl->GetFunction());
+}
+
+void MyObject::New(const FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+
+  if (args.IsConstructCall()) {
+    // Invoked as constructor: `new MyObject(...)`
+    double value = args[0]->IsUndefined() ? 0 : args[0]->NumberValue();
+    MyObject* obj = new MyObject(value);
+    obj->Wrap(args.This());
+    return;
+  } else {
+    // Invoked as plain function `MyObject(...)`, turn into construct call.
+    const int argc = 1;
+    Local<Value> argv[argc] = { args[0] };
+    Local<Function> cons = Local<Function>::New(isolate, constructor);
+    args.GetReturnValue().Set(cons->NewInstance(argc, argv));
+  }
+}
+
+void MyObject::NewInstance(const FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+
+  const unsigned argc = 1;
+  Local<Value> argv[argc] = { args[0] };
+  Local<Function> cons = Local<Function>::New(isolate, constructor);
+  Local<Object> instance = cons->NewInstance(argc, argv);
+
+  args.GetReturnValue().Set(instance);
+}
+
+void MyObject::PlusOne(const FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+
+  MyObject* obj = ObjectWrap::Unwrap<MyObject>(args.Holder());
+  obj->value_ += 1;
+
+  args.GetReturnValue().Set(Number::New(isolate, obj->value_));
+}
+
+} // namespace demo
diff --git a/7_factory_wrap/node_4.x/myobject.h b/7_factory_wrap/node_4.x/myobject.h
new file mode 100644
index 00000000..b592a0c3
--- /dev/null
+++ b/7_factory_wrap/node_4.x/myobject.h
@@ -0,0 +1,32 @@
+#ifndef MYOBJECT_H
+#define MYOBJECT_H
+
+#include <node.h>
+#include <node_object_wrap.h>
+
+namespace demo {
+
+using v8::Function;
+using v8::FunctionCallbackInfo;
+using v8::Isolate;
+using v8::Persistent;
+using v8::Value;
+
+class MyObject : public node::ObjectWrap {
+ public:
+  static void Init(Isolate* isolate);
+  static void NewInstance(const FunctionCallbackInfo<Value>& args);
+
+ private:
+  explicit MyObject(double value = 0);
+  ~MyObject();
+
+  static void New(const FunctionCallbackInfo<Value>& args);
+  static void PlusOne(const FunctionCallbackInfo<Value>& args);
+  static Persistent<Function> constructor;
+  double value_;
+};
+
+} // namespace demo
+
+#endif
diff --git a/7_factory_wrap/node_4.x/package.json b/7_factory_wrap/node_4.x/package.json
new file mode 100644
index 00000000..70fac90e
--- /dev/null
+++ b/7_factory_wrap/node_4.x/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "factory_wrap",
+  "version": "0.0.0",
+  "description": "Node.js Addons Example #7",
+  "main": "addon.js",
+  "private": true,
+  "gypfile": true,
+  "dependencies": {
+    "bindings": "~1.2.1"
+  }
+}
diff --git a/8_passing_wrapped/node_4.x/addon.cc b/8_passing_wrapped/node_4.x/addon.cc
new file mode 100644
index 00000000..4037e66f
--- /dev/null
+++ b/8_passing_wrapped/node_4.x/addon.cc
@@ -0,0 +1,40 @@
+#include <node.h>
+#include <node_object_wrap.h>
+#include "myobject.h"
+
+namespace demo {
+
+using v8::FunctionCallbackInfo;
+using v8::Isolate;
+using v8::Local;
+using v8::Number;
+using v8::Object;
+using v8::String;
+using v8::Value;
+
+void CreateObject(const FunctionCallbackInfo<Value>& args) {
+  MyObject::NewInstance(args);
+}
+
+void Add(const FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+
+  MyObject* obj1 = node::ObjectWrap::Unwrap<MyObject>(
+      args[0]->ToObject());
+  MyObject* obj2 = node::ObjectWrap::Unwrap<MyObject>(
+      args[1]->ToObject());
+
+  double sum = obj1->value() + obj2->value();
+  args.GetReturnValue().Set(Number::New(isolate, sum));
+}
+
+void InitAll(Local<Object> exports) {
+  MyObject::Init(exports->GetIsolate());
+
+  NODE_SET_METHOD(exports, "createObject", CreateObject);
+  NODE_SET_METHOD(exports, "add", Add);
+}
+
+NODE_MODULE(addon, InitAll)
+
+} // namespace demo
diff --git a/8_passing_wrapped/node_4.x/addon.js b/8_passing_wrapped/node_4.x/addon.js
new file mode 100644
index 00000000..42f65e67
--- /dev/null
+++ b/8_passing_wrapped/node_4.x/addon.js
@@ -0,0 +1,7 @@
+const addon = require('bindings')('addon');
+
+const obj1 = addon.createObject(10);
+const obj2 = addon.createObject(20);
+const result = addon.add(obj1, obj2);
+
+console.log(result); // 30
diff --git a/8_passing_wrapped/node_4.x/binding.gyp b/8_passing_wrapped/node_4.x/binding.gyp
new file mode 100644
index 00000000..b05e7abc
--- /dev/null
+++ b/8_passing_wrapped/node_4.x/binding.gyp
@@ -0,0 +1,8 @@
+{
+  "targets": [
+    {
+      "target_name": "addon",
+      "sources": [ "addon.cc", "myobject.cc" ]
+    }
+  ]
+}
diff --git a/8_passing_wrapped/node_4.x/myobject.cc b/8_passing_wrapped/node_4.x/myobject.cc
new file mode 100644
index 00000000..0231f0a1
--- /dev/null
+++ b/8_passing_wrapped/node_4.x/myobject.cc
@@ -0,0 +1,62 @@
+#include <node.h>
+#include "myobject.h"
+
+namespace demo {
+
+using v8::Function;
+using v8::FunctionCallbackInfo;
+using v8::FunctionTemplate;
+using v8::Isolate;
+using v8::Local;
+using v8::Object;
+using v8::Persistent;
+using v8::String;
+using v8::Value;
+
+Persistent<Function> MyObject::constructor;
+
+MyObject::MyObject(double value) : value_(value) {
+}
+
+MyObject::~MyObject() {
+}
+
+void MyObject::Init(Isolate* isolate) {
+  // Prepare constructor template
+  Local<FunctionTemplate> tpl = FunctionTemplate::New(isolate, New);
+  tpl->SetClassName(String::NewFromUtf8(isolate, "MyObject"));
+  tpl->InstanceTemplate()->SetInternalFieldCount(1);
+
+  constructor.Reset(isolate, tpl->GetFunction());
+}
+
+void MyObject::New(const FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+
+  if (args.IsConstructCall()) {
+    // Invoked as constructor: `new MyObject(...)`
+    double value = args[0]->IsUndefined() ? 0 : args[0]->NumberValue();
+    MyObject* obj = new MyObject(value);
+    obj->Wrap(args.This());
+    return;
+  } else {
+    // Invoked as plain function `MyObject(...)`, turn into construct call.
+    const int argc = 1;
+    Local<Value> argv[argc] = { args[0] };
+    Local<Function> cons = Local<Function>::New(isolate, constructor);
+    args.GetReturnValue().Set(cons->NewInstance(argc, argv));
+  }
+}
+
+void MyObject::NewInstance(const FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+
+  const unsigned argc = 1;
+  Local<Value> argv[argc] = { args[0] };
+  Local<Function> cons = Local<Function>::New(isolate, constructor);
+  Local<Object> instance = cons->NewInstance(argc, argv);
+
+  args.GetReturnValue().Set(instance);
+}
+
+} // namespace demo
diff --git a/8_passing_wrapped/node_4.x/myobject.h b/8_passing_wrapped/node_4.x/myobject.h
new file mode 100644
index 00000000..bb6e317a
--- /dev/null
+++ b/8_passing_wrapped/node_4.x/myobject.h
@@ -0,0 +1,32 @@
+#ifndef MYOBJECT_H
+#define MYOBJECT_H
+
+#include <node.h>
+#include <node_object_wrap.h>
+
+namespace demo {
+
+using v8::Function;
+using v8::FunctionCallbackInfo;
+using v8::Isolate;
+using v8::Persistent;
+using v8::Value;
+
+class MyObject : public node::ObjectWrap {
+ public:
+  static void Init(v8::Isolate* Isolate);
+  static void NewInstance(const v8::FunctionCallbackInfo<v8::Value>& args);
+  inline double value() const { return value_; }
+
+ private:
+  explicit MyObject(double value = 0);
+  ~MyObject();
+
+  static void New(const v8::FunctionCallbackInfo<v8::Value>& args);
+  static v8::Persistent<v8::Function> constructor;
+  double value_;
+};
+
+} // namespace demo
+
+#endif
diff --git a/8_passing_wrapped/node_4.x/package.json b/8_passing_wrapped/node_4.x/package.json
new file mode 100644
index 00000000..5c446be0
--- /dev/null
+++ b/8_passing_wrapped/node_4.x/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "passing_wrapped",
+  "version": "0.0.0",
+  "description": "Node.js Addons Example #8",
+  "main": "addon.js",
+  "private": true,
+  "gypfile": true,
+  "dependencies": {
+    "bindings": "~1.2.1"
+  }
+}