diff --git a/csharp/src/AddressBook/AddPerson.cs b/csharp/src/AddressBook/AddPerson.cs
new file mode 100644
index 0000000..6eeb9f6
--- /dev/null
+++ b/csharp/src/AddressBook/AddPerson.cs
@@ -0,0 +1,132 @@
+﻿#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#endregion
+
+using System;
+using System.IO;
+
+namespace Google.Protobuf.Examples.AddressBook
+{
+    internal class AddPerson
+    {
+        /// <summary>
+        /// Builds a person based on user input
+        /// </summary>
+        private static Person PromptForAddress(TextReader input, TextWriter output)
+        {
+            Person person = new Person();
+
+            output.Write("Enter person ID: ");
+            person.Id = int.Parse(input.ReadLine());
+
+            output.Write("Enter name: ");
+            person.Name = input.ReadLine();
+
+            output.Write("Enter email address (blank for none): ");
+            string email = input.ReadLine();
+            if (email.Length > 0)
+            {
+                person.Email = email;
+            }
+
+            while (true)
+            {
+                output.Write("Enter a phone number (or leave blank to finish): ");
+                string number = input.ReadLine();
+                if (number.Length == 0)
+                {
+                    break;
+                }
+
+                Person.Types.PhoneNumber phoneNumber = new Person.Types.PhoneNumber { Number = number };
+
+                output.Write("Is this a mobile, home, or work phone? ");
+                String type = input.ReadLine();
+                switch (type)
+                {
+                    case "mobile":
+                        phoneNumber.Type = Person.Types.PhoneType.MOBILE;
+                        break;
+                    case "home":
+                        phoneNumber.Type = Person.Types.PhoneType.HOME;
+                        break;
+                    case "work":
+                        phoneNumber.Type = Person.Types.PhoneType.WORK;
+                        break;
+                    default:
+                        output.Write("Unknown phone type. Using default.");
+                        break;
+                }
+
+                person.Phones.Add(phoneNumber);
+            }
+            return person;
+        }
+
+        /// <summary>
+        /// Entry point - loads an existing addressbook or creates a new one,
+        /// then writes it back to the file.
+        /// </summary>
+        public static int Main(string[] args)
+        {
+            if (args.Length != 1)
+            {
+                Console.Error.WriteLine("Usage:  AddPerson ADDRESS_BOOK_FILE");
+                return -1;
+            }
+
+            AddressBook addressBook;
+
+            if (File.Exists(args[0]))
+            {
+                using (Stream file = File.OpenRead(args[0]))
+                {
+                    addressBook = AddressBook.Parser.ParseFrom(file);
+                }
+            }
+            else
+            {
+                Console.WriteLine("{0}: File not found. Creating a new file.", args[0]);
+                addressBook = new AddressBook();
+            }
+
+            // Add an address.
+            addressBook.People.Add(PromptForAddress(Console.In, Console.Out));
+
+            // Write the new address book back to disk.
+            using (Stream output = File.OpenWrite(args[0]))
+            {
+                addressBook.WriteTo(output);
+            }
+            return 0;
+        }
+    }
+}
\ No newline at end of file
diff --git a/csharp/src/AddressBook/AddressBook.csproj b/csharp/src/AddressBook/AddressBook.csproj
new file mode 100644
index 0000000..8f8ca7e
--- /dev/null
+++ b/csharp/src/AddressBook/AddressBook.csproj
@@ -0,0 +1,75 @@
+﻿<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProductVersion>9.0.30729</ProductVersion>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectGuid>{A31F5FB2-4FF3-432A-B35B-5CD203606311}</ProjectGuid>
+    <OutputType>Exe</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>Google.Protobuf.Examples.AddressBook</RootNamespace>
+    <AssemblyName>AddressBook</AssemblyName>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <StartupObject>Google.Protobuf.Examples.AddressBook.Program</StartupObject>
+    <TargetFrameworkProfile>
+    </TargetFrameworkProfile>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug</OutputPath>
+    <IntermediateOutputPath>obj\Debug\</IntermediateOutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <NoStdLib>true</NoStdLib>
+    <GenerateSerializationAssemblies>Off</GenerateSerializationAssemblies>
+    <Prefer32Bit>false</Prefer32Bit>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release</OutputPath>
+    <IntermediateOutputPath>obj\Release\</IntermediateOutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <NoStdLib>true</NoStdLib>
+    <GenerateSerializationAssemblies>Off</GenerateSerializationAssemblies>
+    <Prefer32Bit>false</Prefer32Bit>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="mscorlib" />
+    <Reference Include="System" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="AddPerson.cs" />
+    <Compile Include="Addressbook.cs" />
+    <Compile Include="SampleUsage.cs" />
+    <Compile Include="ListPeople.cs" />
+    <Compile Include="Program.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\Google.Protobuf\Google.Protobuf.csproj">
+      <Project>{6908BDCE-D925-43F3-94AC-A531E6DF2591}</Project>
+      <Name>Google.Protobuf</Name>
+    </ProjectReference>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="app.config" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>
\ No newline at end of file
diff --git a/csharp/src/AddressBook/Addressbook.cs b/csharp/src/AddressBook/Addressbook.cs
new file mode 100644
index 0000000..166dd49
--- /dev/null
+++ b/csharp/src/AddressBook/Addressbook.cs
@@ -0,0 +1,473 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: addressbook.proto
+#pragma warning disable 1591, 0612, 3021
+#region Designer generated code
+
+using pb = global::Google.Protobuf;
+using pbc = global::Google.Protobuf.Collections;
+using pbr = global::Google.Protobuf.Reflection;
+using scg = global::System.Collections.Generic;
+namespace Google.Protobuf.Examples.AddressBook {
+
+  /// <summary>Holder for reflection information generated from addressbook.proto</summary>
+  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
+  public static partial class AddressbookReflection {
+
+    #region Descriptor
+    /// <summary>File descriptor for addressbook.proto</summary>
+    public static pbr::FileDescriptor Descriptor {
+      get { return descriptor; }
+    }
+    private static pbr::FileDescriptor descriptor;
+
+    static AddressbookReflection() {
+      byte[] descriptorData = global::System.Convert.FromBase64String(
+          string.Concat(
+            "ChFhZGRyZXNzYm9vay5wcm90bxIIdHV0b3JpYWwi1QEKBlBlcnNvbhIMCgRu",
+            "YW1lGAEgASgJEgoKAmlkGAIgASgFEg0KBWVtYWlsGAMgASgJEiwKBnBob25l",
+            "cxgEIAMoCzIcLnR1dG9yaWFsLlBlcnNvbi5QaG9uZU51bWJlchpHCgtQaG9u",
+            "ZU51bWJlchIOCgZudW1iZXIYASABKAkSKAoEdHlwZRgCIAEoDjIaLnR1dG9y",
+            "aWFsLlBlcnNvbi5QaG9uZVR5cGUiKwoJUGhvbmVUeXBlEgoKBk1PQklMRRAA",
+            "EggKBEhPTUUQARIICgRXT1JLEAIiLwoLQWRkcmVzc0Jvb2sSIAoGcGVvcGxl",
+            "GAEgAygLMhAudHV0b3JpYWwuUGVyc29uQlAKFGNvbS5leGFtcGxlLnR1dG9y",
+            "aWFsQhFBZGRyZXNzQm9va1Byb3Rvc6oCJEdvb2dsZS5Qcm90b2J1Zi5FeGFt",
+            "cGxlcy5BZGRyZXNzQm9va2IGcHJvdG8z"));
+      descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
+          new pbr::FileDescriptor[] { },
+          new pbr::GeneratedClrTypeInfo(null, new pbr::GeneratedClrTypeInfo[] {
+            new pbr::GeneratedClrTypeInfo(typeof(global::Google.Protobuf.Examples.AddressBook.Person), global::Google.Protobuf.Examples.AddressBook.Person.Parser, new[]{ "Name", "Id", "Email", "Phones" }, null, new[]{ typeof(global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType) }, new pbr::GeneratedClrTypeInfo[] { new pbr::GeneratedClrTypeInfo(typeof(global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneNumber), global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneNumber.Parser, new[]{ "Number", "Type" }, null, null, null)}),
+            new pbr::GeneratedClrTypeInfo(typeof(global::Google.Protobuf.Examples.AddressBook.AddressBook), global::Google.Protobuf.Examples.AddressBook.AddressBook.Parser, new[]{ "People" }, null, null, null)
+          }));
+    }
+    #endregion
+
+  }
+  #region Messages
+  /// <summary>
+  ///  [START messages]
+  /// </summary>
+  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
+  public sealed partial class Person : pb::IMessage<Person> {
+    private static readonly pb::MessageParser<Person> _parser = new pb::MessageParser<Person>(() => new Person());
+    public static pb::MessageParser<Person> Parser { get { return _parser; } }
+
+    public static pbr::MessageDescriptor Descriptor {
+      get { return global::Google.Protobuf.Examples.AddressBook.AddressbookReflection.Descriptor.MessageTypes[0]; }
+    }
+
+    pbr::MessageDescriptor pb::IMessage.Descriptor {
+      get { return Descriptor; }
+    }
+
+    public Person() {
+      OnConstruction();
+    }
+
+    partial void OnConstruction();
+
+    public Person(Person other) : this() {
+      name_ = other.name_;
+      id_ = other.id_;
+      email_ = other.email_;
+      phones_ = other.phones_.Clone();
+    }
+
+    public Person Clone() {
+      return new Person(this);
+    }
+
+    /// <summary>Field number for the "name" field.</summary>
+    public const int NameFieldNumber = 1;
+    private string name_ = "";
+    public string Name {
+      get { return name_; }
+      set {
+        name_ = pb::ProtoPreconditions.CheckNotNull(value, "value");
+      }
+    }
+
+    /// <summary>Field number for the "id" field.</summary>
+    public const int IdFieldNumber = 2;
+    private int id_;
+    /// <summary>
+    ///  Unique ID number for this person.
+    /// </summary>
+    public int Id {
+      get { return id_; }
+      set {
+        id_ = value;
+      }
+    }
+
+    /// <summary>Field number for the "email" field.</summary>
+    public const int EmailFieldNumber = 3;
+    private string email_ = "";
+    public string Email {
+      get { return email_; }
+      set {
+        email_ = pb::ProtoPreconditions.CheckNotNull(value, "value");
+      }
+    }
+
+    /// <summary>Field number for the "phones" field.</summary>
+    public const int PhonesFieldNumber = 4;
+    private static readonly pb::FieldCodec<global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneNumber> _repeated_phones_codec
+        = pb::FieldCodec.ForMessage(34, global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneNumber.Parser);
+    private readonly pbc::RepeatedField<global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneNumber> phones_ = new pbc::RepeatedField<global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneNumber>();
+    public pbc::RepeatedField<global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneNumber> Phones {
+      get { return phones_; }
+    }
+
+    public override bool Equals(object other) {
+      return Equals(other as Person);
+    }
+
+    public bool Equals(Person other) {
+      if (ReferenceEquals(other, null)) {
+        return false;
+      }
+      if (ReferenceEquals(other, this)) {
+        return true;
+      }
+      if (Name != other.Name) return false;
+      if (Id != other.Id) return false;
+      if (Email != other.Email) return false;
+      if(!phones_.Equals(other.phones_)) return false;
+      return true;
+    }
+
+    public override int GetHashCode() {
+      int hash = 1;
+      if (Name.Length != 0) hash ^= Name.GetHashCode();
+      if (Id != 0) hash ^= Id.GetHashCode();
+      if (Email.Length != 0) hash ^= Email.GetHashCode();
+      hash ^= phones_.GetHashCode();
+      return hash;
+    }
+
+    public override string ToString() {
+      return pb::JsonFormatter.ToDiagnosticString(this);
+    }
+
+    public void WriteTo(pb::CodedOutputStream output) {
+      if (Name.Length != 0) {
+        output.WriteRawTag(10);
+        output.WriteString(Name);
+      }
+      if (Id != 0) {
+        output.WriteRawTag(16);
+        output.WriteInt32(Id);
+      }
+      if (Email.Length != 0) {
+        output.WriteRawTag(26);
+        output.WriteString(Email);
+      }
+      phones_.WriteTo(output, _repeated_phones_codec);
+    }
+
+    public int CalculateSize() {
+      int size = 0;
+      if (Name.Length != 0) {
+        size += 1 + pb::CodedOutputStream.ComputeStringSize(Name);
+      }
+      if (Id != 0) {
+        size += 1 + pb::CodedOutputStream.ComputeInt32Size(Id);
+      }
+      if (Email.Length != 0) {
+        size += 1 + pb::CodedOutputStream.ComputeStringSize(Email);
+      }
+      size += phones_.CalculateSize(_repeated_phones_codec);
+      return size;
+    }
+
+    public void MergeFrom(Person other) {
+      if (other == null) {
+        return;
+      }
+      if (other.Name.Length != 0) {
+        Name = other.Name;
+      }
+      if (other.Id != 0) {
+        Id = other.Id;
+      }
+      if (other.Email.Length != 0) {
+        Email = other.Email;
+      }
+      phones_.Add(other.phones_);
+    }
+
+    public void MergeFrom(pb::CodedInputStream input) {
+      uint tag;
+      while ((tag = input.ReadTag()) != 0) {
+        switch(tag) {
+          default:
+            input.SkipLastField();
+            break;
+          case 10: {
+            Name = input.ReadString();
+            break;
+          }
+          case 16: {
+            Id = input.ReadInt32();
+            break;
+          }
+          case 26: {
+            Email = input.ReadString();
+            break;
+          }
+          case 34: {
+            phones_.AddEntriesFrom(input, _repeated_phones_codec);
+            break;
+          }
+        }
+      }
+    }
+
+    #region Nested types
+    /// <summary>Container for nested types declared in the Person message type.</summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
+    public static partial class Types {
+      public enum PhoneType {
+        MOBILE = 0,
+        HOME = 1,
+        WORK = 2,
+      }
+
+      [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
+      public sealed partial class PhoneNumber : pb::IMessage<PhoneNumber> {
+        private static readonly pb::MessageParser<PhoneNumber> _parser = new pb::MessageParser<PhoneNumber>(() => new PhoneNumber());
+        public static pb::MessageParser<PhoneNumber> Parser { get { return _parser; } }
+
+        public static pbr::MessageDescriptor Descriptor {
+          get { return global::Google.Protobuf.Examples.AddressBook.Person.Descriptor.NestedTypes[0]; }
+        }
+
+        pbr::MessageDescriptor pb::IMessage.Descriptor {
+          get { return Descriptor; }
+        }
+
+        public PhoneNumber() {
+          OnConstruction();
+        }
+
+        partial void OnConstruction();
+
+        public PhoneNumber(PhoneNumber other) : this() {
+          number_ = other.number_;
+          type_ = other.type_;
+        }
+
+        public PhoneNumber Clone() {
+          return new PhoneNumber(this);
+        }
+
+        /// <summary>Field number for the "number" field.</summary>
+        public const int NumberFieldNumber = 1;
+        private string number_ = "";
+        public string Number {
+          get { return number_; }
+          set {
+            number_ = pb::ProtoPreconditions.CheckNotNull(value, "value");
+          }
+        }
+
+        /// <summary>Field number for the "type" field.</summary>
+        public const int TypeFieldNumber = 2;
+        private global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType type_ = global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType.MOBILE;
+        public global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType Type {
+          get { return type_; }
+          set {
+            type_ = value;
+          }
+        }
+
+        public override bool Equals(object other) {
+          return Equals(other as PhoneNumber);
+        }
+
+        public bool Equals(PhoneNumber other) {
+          if (ReferenceEquals(other, null)) {
+            return false;
+          }
+          if (ReferenceEquals(other, this)) {
+            return true;
+          }
+          if (Number != other.Number) return false;
+          if (Type != other.Type) return false;
+          return true;
+        }
+
+        public override int GetHashCode() {
+          int hash = 1;
+          if (Number.Length != 0) hash ^= Number.GetHashCode();
+          if (Type != global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType.MOBILE) hash ^= Type.GetHashCode();
+          return hash;
+        }
+
+        public override string ToString() {
+          return pb::JsonFormatter.ToDiagnosticString(this);
+        }
+
+        public void WriteTo(pb::CodedOutputStream output) {
+          if (Number.Length != 0) {
+            output.WriteRawTag(10);
+            output.WriteString(Number);
+          }
+          if (Type != global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType.MOBILE) {
+            output.WriteRawTag(16);
+            output.WriteEnum((int) Type);
+          }
+        }
+
+        public int CalculateSize() {
+          int size = 0;
+          if (Number.Length != 0) {
+            size += 1 + pb::CodedOutputStream.ComputeStringSize(Number);
+          }
+          if (Type != global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType.MOBILE) {
+            size += 1 + pb::CodedOutputStream.ComputeEnumSize((int) Type);
+          }
+          return size;
+        }
+
+        public void MergeFrom(PhoneNumber other) {
+          if (other == null) {
+            return;
+          }
+          if (other.Number.Length != 0) {
+            Number = other.Number;
+          }
+          if (other.Type != global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType.MOBILE) {
+            Type = other.Type;
+          }
+        }
+
+        public void MergeFrom(pb::CodedInputStream input) {
+          uint tag;
+          while ((tag = input.ReadTag()) != 0) {
+            switch(tag) {
+              default:
+                input.SkipLastField();
+                break;
+              case 10: {
+                Number = input.ReadString();
+                break;
+              }
+              case 16: {
+                type_ = (global::Google.Protobuf.Examples.AddressBook.Person.Types.PhoneType) input.ReadEnum();
+                break;
+              }
+            }
+          }
+        }
+
+      }
+
+    }
+    #endregion
+
+  }
+
+  /// <summary>
+  ///  Our address book file is just one of these.
+  /// </summary>
+  [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
+  public sealed partial class AddressBook : pb::IMessage<AddressBook> {
+    private static readonly pb::MessageParser<AddressBook> _parser = new pb::MessageParser<AddressBook>(() => new AddressBook());
+    public static pb::MessageParser<AddressBook> Parser { get { return _parser; } }
+
+    public static pbr::MessageDescriptor Descriptor {
+      get { return global::Google.Protobuf.Examples.AddressBook.AddressbookReflection.Descriptor.MessageTypes[1]; }
+    }
+
+    pbr::MessageDescriptor pb::IMessage.Descriptor {
+      get { return Descriptor; }
+    }
+
+    public AddressBook() {
+      OnConstruction();
+    }
+
+    partial void OnConstruction();
+
+    public AddressBook(AddressBook other) : this() {
+      people_ = other.people_.Clone();
+    }
+
+    public AddressBook Clone() {
+      return new AddressBook(this);
+    }
+
+    /// <summary>Field number for the "people" field.</summary>
+    public const int PeopleFieldNumber = 1;
+    private static readonly pb::FieldCodec<global::Google.Protobuf.Examples.AddressBook.Person> _repeated_people_codec
+        = pb::FieldCodec.ForMessage(10, global::Google.Protobuf.Examples.AddressBook.Person.Parser);
+    private readonly pbc::RepeatedField<global::Google.Protobuf.Examples.AddressBook.Person> people_ = new pbc::RepeatedField<global::Google.Protobuf.Examples.AddressBook.Person>();
+    public pbc::RepeatedField<global::Google.Protobuf.Examples.AddressBook.Person> People {
+      get { return people_; }
+    }
+
+    public override bool Equals(object other) {
+      return Equals(other as AddressBook);
+    }
+
+    public bool Equals(AddressBook other) {
+      if (ReferenceEquals(other, null)) {
+        return false;
+      }
+      if (ReferenceEquals(other, this)) {
+        return true;
+      }
+      if(!people_.Equals(other.people_)) return false;
+      return true;
+    }
+
+    public override int GetHashCode() {
+      int hash = 1;
+      hash ^= people_.GetHashCode();
+      return hash;
+    }
+
+    public override string ToString() {
+      return pb::JsonFormatter.ToDiagnosticString(this);
+    }
+
+    public void WriteTo(pb::CodedOutputStream output) {
+      people_.WriteTo(output, _repeated_people_codec);
+    }
+
+    public int CalculateSize() {
+      int size = 0;
+      size += people_.CalculateSize(_repeated_people_codec);
+      return size;
+    }
+
+    public void MergeFrom(AddressBook other) {
+      if (other == null) {
+        return;
+      }
+      people_.Add(other.people_);
+    }
+
+    public void MergeFrom(pb::CodedInputStream input) {
+      uint tag;
+      while ((tag = input.ReadTag()) != 0) {
+        switch(tag) {
+          default:
+            input.SkipLastField();
+            break;
+          case 10: {
+            people_.AddEntriesFrom(input, _repeated_people_codec);
+            break;
+          }
+        }
+      }
+    }
+
+  }
+
+  #endregion
+
+}
+
+#endregion Designer generated code
diff --git a/csharp/src/AddressBook/ListPeople.cs b/csharp/src/AddressBook/ListPeople.cs
new file mode 100644
index 0000000..3979430
--- /dev/null
+++ b/csharp/src/AddressBook/ListPeople.cs
@@ -0,0 +1,99 @@
+﻿#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#endregion
+
+using System;
+using System.IO;
+
+namespace Google.Protobuf.Examples.AddressBook
+{
+    internal class ListPeople
+    {
+        /// <summary>
+        /// Iterates though all people in the AddressBook and prints info about them.
+        /// </summary>
+        private static void Print(AddressBook addressBook)
+        {
+            foreach (Person person in addressBook.People)
+            {
+                Console.WriteLine("Person ID: {0}", person.Id);
+                Console.WriteLine("  Name: {0}", person.Name);
+                if (person.Email != "")
+                {
+                    Console.WriteLine("  E-mail address: {0}", person.Email);
+                }
+
+                foreach (Person.Types.PhoneNumber phoneNumber in person.Phones)
+                {
+                    switch (phoneNumber.Type)
+                    {
+                        case Person.Types.PhoneType.MOBILE:
+                            Console.Write("  Mobile phone #: ");
+                            break;
+                        case Person.Types.PhoneType.HOME:
+                            Console.Write("  Home phone #: ");
+                            break;
+                        case Person.Types.PhoneType.WORK:
+                            Console.Write("  Work phone #: ");
+                            break;
+                    }
+                    Console.WriteLine(phoneNumber.Number);
+                }
+            }
+        }
+
+        /// <summary>
+        /// Entry point - loads the addressbook and then displays it.
+        /// </summary>
+        public static int Main(string[] args)
+        {
+            if (args.Length != 1)
+            {
+                Console.Error.WriteLine("Usage:  ListPeople ADDRESS_BOOK_FILE");
+                return 1;
+            }
+
+            if (!File.Exists(args[0]))
+            {
+                Console.WriteLine("{0} doesn't exist. Add a person to create the file first.", args[0]);
+                return 0;
+            }
+
+            // Read the existing address book.
+            using (Stream stream = File.OpenRead(args[0]))
+            {
+                AddressBook addressBook = AddressBook.Parser.ParseFrom(stream);
+                Print(addressBook);
+            }
+            return 0;
+        }
+    }
+}
\ No newline at end of file
diff --git a/csharp/src/AddressBook/Program.cs b/csharp/src/AddressBook/Program.cs
new file mode 100644
index 0000000..ff7b9c0
--- /dev/null
+++ b/csharp/src/AddressBook/Program.cs
@@ -0,0 +1,95 @@
+﻿#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#endregion
+
+using System;
+
+namespace Google.Protobuf.Examples.AddressBook
+{
+    /// <summary>
+    /// Entry point. Repeatedly prompts user for an action to take, delegating actual behaviour
+    /// to individual actions. Each action has its own Main method, so that it can be used as an
+    /// invidual complete program.
+    /// </summary>
+    internal class Program
+    {
+        private static int Main(string[] args)
+        {
+            if (args.Length > 1)
+            {
+                Console.Error.WriteLine("Usage: AddressBook [file]");
+                Console.Error.WriteLine("If the filename isn't specified, \"addressbook.data\" is used instead.");
+                return 1;
+            }
+            string addressBookFile = args.Length > 0 ? args[0] : "addressbook.data";
+
+            bool stopping = false;
+            while (!stopping)
+            {
+                Console.WriteLine("Options:");
+                Console.WriteLine("  L: List contents");
+                Console.WriteLine("  A: Add new person");
+                Console.WriteLine("  Q: Quit");
+                Console.Write("Action? ");
+                Console.Out.Flush();
+                char choice = Console.ReadKey().KeyChar;
+                Console.WriteLine();
+                try
+                {
+                    switch (choice)
+                    {
+                        case 'A':
+                        case 'a':
+                            AddPerson.Main(new string[] {addressBookFile});
+                            break;
+                        case 'L':
+                        case 'l':
+                            ListPeople.Main(new string[] {addressBookFile});
+                            break;
+                        case 'Q':
+                        case 'q':
+                            stopping = true;
+                            break;
+                        default:
+                            Console.WriteLine("Unknown option: {0}", choice);
+                            break;
+                    }
+                }
+                catch (Exception e)
+                {
+                    Console.WriteLine("Exception executing action: {0}", e);
+                }
+                Console.WriteLine();
+            }
+            return 0;
+        }
+    }
+}
\ No newline at end of file
diff --git a/csharp/src/AddressBook/Properties/AssemblyInfo.cs b/csharp/src/AddressBook/Properties/AssemblyInfo.cs
new file mode 100644
index 0000000..9cb014c
--- /dev/null
+++ b/csharp/src/AddressBook/Properties/AssemblyInfo.cs
@@ -0,0 +1,18 @@
+using System.Reflection;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following 
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+
+[assembly: AssemblyTitle("AddressBook")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("AddressBook")]
+[assembly: AssemblyCopyright("Copyright ©  2015")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+[assembly: AssemblyVersion("3.0.0.0")]
+[assembly: AssemblyFileVersion("3.0.0.0")]
diff --git a/csharp/src/AddressBook/SampleUsage.cs b/csharp/src/AddressBook/SampleUsage.cs
new file mode 100644
index 0000000..aaaedda
--- /dev/null
+++ b/csharp/src/AddressBook/SampleUsage.cs
@@ -0,0 +1,73 @@
+﻿#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#endregion
+    
+using System;
+using System.IO;
+
+namespace Google.Protobuf.Examples.AddressBook
+{
+    internal class SampleUsage
+    {
+        private static void Main()
+        {
+            byte[] bytes;
+            // Create a new person
+            Person person = new Person
+            {
+                Id = 1,
+                Name = "Foo",
+                Email = "foo@bar",
+                Phones = { new Person.Types.PhoneNumber { Number = "555-1212" } }
+            };
+            using (MemoryStream stream = new MemoryStream())
+            {
+                // Save the person to a stream
+                person.WriteTo(stream);
+                bytes = stream.ToArray();
+            }
+            Person copy = Person.Parser.ParseFrom(bytes);
+
+            AddressBook book = new AddressBook
+            {
+                People = { copy }
+            };
+            bytes = book.ToByteArray();
+            // And read the address book back again
+            AddressBook restored = AddressBook.Parser.ParseFrom(bytes);
+            // The message performs a deep-comparison on equality:
+            if (restored.People.Count != 1 || !person.Equals(restored.People[0]))
+            {
+                throw new ApplicationException("There is a bad person in here!");
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/csharp/src/AddressBook/app.config b/csharp/src/AddressBook/app.config
new file mode 100644
index 0000000..a80813a
--- /dev/null
+++ b/csharp/src/AddressBook/app.config
@@ -0,0 +1,3 @@
+<?xml version="1.0"?>
+<configuration>
+	<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5"/></startup></configuration>