diff --git a/app/controllers/messages_controller.rb b/app/controllers/messages_controller.rb
new file mode 100644
--- /dev/null
+++ b/app/controllers/messages_controller.rb
@@ -0,0 +1,73 @@
+class MessagesController < ApplicationController
+
+  before_filter :authenticate
+
+  verify :method => :post, :only => ['create'],
+         :redirect_to => { :action => 'list' }
+
+  before_filter :only => ['console','show'] do |controller| 
+    controller.authorization_by_roles(['admin'])
+  end
+
+  def list
+    @user = User.find(session[:user_id])
+    @messages = Message.find_all_sent_by_user(@user)
+  end
+  
+  def console
+    @user = User.find(session[:user_id])
+    @messages = Message.find_all_system_unreplied_messages
+  end
+
+  def show
+    @message = Message.find(params[:id])
+  end
+
+  def create
+    user = User.find(session[:user_id])
+    @message = Message.new(params[:message])
+    @message.sender = user
+    if !@message.save
+      render :action => 'list' and return
+    else
+      flash[:notice] = 'New message posted'
+      redirect_to :action => 'list'
+    end
+  end
+
+  def reply
+    user = User.find(session[:user_id])
+    @message = Message.new(params[:r_message])
+    @message.sender = user
+    if !@message.save
+      render :action => 'show' and return
+    else
+      flash[:notice] = 'Message replied'
+      rep_msg = @message.replying_message
+      rep_msg.replied = true
+      rep_msg.save
+      redirect_to :action => 'console'
+    end
+  end
+
+  protected
+  def build_replying_message_hierarchy(user)
+    @all_messages = {}
+
+
+    # manually build replies hierarchy (to improve efficiency)
+    [@messages, @replied_messages].each do |collection|
+      collection.each do |m| 
+        @all_messages[m.id] = {:msg => m, :replies => []}
+      end
+    end
+
+    @all_messages.each do |m|
+      rep_id = m.replying_message_id
+      if @all_messages[rep_id]!=nil
+        @all_messages[rep_id][:replies] << m
+      end
+    end
+  end
+
+end
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -9,6 +9,7 @@
       # admin menu
       menu_items << "<b>Administrative task:</b> "
       append_to menu_items, '[Announcements]', 'announcements', 'index'
+      append_to menu_items, '[Msg console]', 'messages', 'console'
       append_to menu_items, '[Problem admin]', 'problems', 'index'
       append_to menu_items, '[User admin]', 'user_admin', 'index'
       append_to menu_items, '[User stat]', 'user_admin', 'user_stat'
@@ -19,6 +20,7 @@
 
     # main page
     append_to menu_items, '[Main]', 'main', 'list'
+    append_to menu_items, '[Messages]', 'messages', 'list'
     append_to menu_items, '[Tasks]', 'tasks', 'list'
     append_to menu_items, '[Submissions]', 'main', 'submission'
     append_to menu_items, '[Test]', 'test', 'index'
diff --git a/app/helpers/messages_helper.rb b/app/helpers/messages_helper.rb
new file mode 100644
--- /dev/null
+++ b/app/helpers/messages_helper.rb
@@ -0,0 +1,2 @@
+module MessagesHelper
+end
diff --git a/app/models/message.rb b/app/models/message.rb
new file mode 100644
--- /dev/null
+++ b/app/models/message.rb
@@ -0,0 +1,60 @@
+class Message < ActiveRecord::Base
+
+  belongs_to :sender, :class_name => "User"
+  belongs_to :receiver, :class_name => "User"
+
+  belongs_to :replying_message, :class_name => "Message"
+
+  # commented manually do it
+  #
+  #has_many :replied_messages, {
+  #  :class_name => "Message", 
+  #  :foreign_key => "replying_message_id"
+  #}
+  #
+
+  attr_accessor :replied_messages
+
+  def self.find_all_sent_by_user(user)
+    messages = user.messages
+    replied_messages = user.replied_messages
+    Message.build_replying_message_hierarchy messages, replied_messages
+    return messages
+  end
+  
+  def self.find_all_system_unreplied_messages
+    self.find(:all, 
+              :conditions => 'ISNULL(receiver_id) ' + 
+                             'AND (ISNULL(replied) OR replied=0)',
+              :order => 'created_at')
+  end
+
+  def self.build_replying_message_hierarchy(*args)
+    # manually build replies hierarchy (to improve efficiency)
+    all_messages = {}
+
+    args.each do |collection|
+      collection.each do |m| 
+        all_messages[m.id] = m
+        m.replied_messages = []
+      end
+    end
+
+    all_messages.each_value do |m|
+      rep_id = m.replying_message_id
+      if all_messages[rep_id]!=nil
+        all_messages[rep_id].add_replied_message(m)
+      end
+    end
+  end
+
+  def add_replied_message(m)
+    if @replied_messages==nil
+      @replied_messages = [m]
+    else
+      @replied_messages << m
+    end
+    @replied_messages
+  end
+
+end
diff --git a/app/models/user.rb b/app/models/user.rb
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -6,6 +6,16 @@
 
   has_many :test_requests, :order => "submitted_at DESC"
 
+  has_many :messages, 
+           :class_name => "Message",
+           :foreign_key => "sender_id", 
+           :order => 'created_at DESC'
+
+  has_many :replied_messages, 
+           :class_name => "Message",
+           :foreign_key => "receiver_id", 
+           :order => 'created_at DESC'
+
   belongs_to :site
 
   validates_presence_of :login
diff --git a/app/views/messages/_message.html.haml b/app/views/messages/_message.html.haml
new file mode 100644
--- /dev/null
+++ b/app/views/messages/_message.html.haml
@@ -0,0 +1,7 @@
+.message
+  .stat
+    = "#{message.sender.full_name} at #{message.created_at}"
+  %div{:class => (!defined?(reply) or (reply==false)) ? "body" : "reply-body"}
+    = simple_format(message.body)
+  - if message.replied_messages.length!=0
+    = render :partial => 'message', :collection => message.replied_messages, :locals => {:reply => true}
diff --git a/app/views/messages/_short_message.html.haml b/app/views/messages/_short_message.html.haml
new file mode 100644
--- /dev/null
+++ b/app/views/messages/_short_message.html.haml
@@ -0,0 +1,6 @@
+%tr
+  %td=h short_message.sender.full_name
+  %td= "#{short_message.created_at}"
+  %td=h truncate(short_message.body)
+  %td
+    = link_to "[reply]", :action => 'show', :id => short_message.id
diff --git a/app/views/messages/console.html.haml b/app/views/messages/console.html.haml
new file mode 100644
--- /dev/null
+++ b/app/views/messages/console.html.haml
@@ -0,0 +1,13 @@
+= user_title_bar(@user)
+
+%h1 Console: active messages
+
+= link_to '[all messages]', :action => 'list_all'
+
+%table
+  %tr
+    %th From
+    %th When
+    %th Message
+    %th
+  = render :partial => "short_message", :collection => @messages
diff --git a/app/views/messages/list.html.haml b/app/views/messages/list.html.haml
new file mode 100644
--- /dev/null
+++ b/app/views/messages/list.html.haml
@@ -0,0 +1,14 @@
+= user_title_bar(@user)
+
+%h3 Your Messages
+
+- form_for 'message', nil, :url => { :action => 'create'} do |f|
+  %p 
+    %b New message
+    = submit_tag "Post"
+    %br/
+    = f.text_area :body, :rows => 5, :cols => 100
+
+%hr/
+
+= render :partial => 'message', :collection => @messages, :locals => {:reply => false}
diff --git a/app/views/messages/show.html.haml b/app/views/messages/show.html.haml
new file mode 100644
--- /dev/null
+++ b/app/views/messages/show.html.haml
@@ -0,0 +1,13 @@
+%h3 Message
+
+.message
+  .stat
+    = "#{@message.sender.full_name} at #{@message.created_at}"
+  .body= simple_format(@message.body)
+
+%h3 Your reply:
+- form_for 'r_message', nil, :url => { :action => 'reply'} do |f|
+  = f.text_area :body, :rows => 5, :cols => 100
+  = f.hidden_field :receiver_id, {:value => @message.sender_id }
+  = f.hidden_field :replying_message_id, {:value => @message.id }
+  = submit_tag "Post"
diff --git a/db/migrate/032_create_messages.rb b/db/migrate/032_create_messages.rb
new file mode 100644
--- /dev/null
+++ b/db/migrate/032_create_messages.rb
@@ -0,0 +1,17 @@
+class CreateMessages < ActiveRecord::Migration
+  def self.up
+    create_table :messages do |t|
+      t.column "sender_id", :integer
+      t.column "receiver_id", :integer
+      t.column "replying_message_id", :integer
+      t.column "body", :text
+      t.column "replied", :boolean   # this is for efficiency
+      
+      t.timestamps
+    end
+  end
+
+  def self.down
+    drop_table :messages
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -9,7 +9,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 31) do
+ActiveRecord::Schema.define(:version => 32) do
 
   create_table "announcements", :force => true do |t|
     t.string   "author"
@@ -52,6 +52,16 @@
     t.string "ext",         :limit => 10
   end
 
+  create_table "messages", :force => true do |t|
+    t.integer  "sender_id"
+    t.integer  "receiver_id"
+    t.integer  "replying_message_id"
+    t.text     "body"
+    t.boolean  "replied"
+    t.datetime "created_at"
+    t.datetime "updated_at"
+  end
+
   create_table "problems", :force => true do |t|
     t.string  "name",           :limit => 30
     t.string  "full_name"
diff --git a/public/stylesheets/application.css b/public/stylesheets/application.css
--- a/public/stylesheets/application.css
+++ b/public/stylesheets/application.css
@@ -191,3 +191,31 @@
     font-style: italic;
     font-size: 9px;
 }
+
+/******************
+  [Messages
+******************/
+
+div.message {
+    padding-top: 5px;
+    padding-left: 10px;
+}
+
+div.message div.body {
+    border: 1px solid green;
+    background: #eeffee;
+    padding-left: 5px;
+}
+
+div.message div.reply-body {
+    border: 1px solid black;
+    background: #ffeeee;
+    padding-left: 5px;
+}
+
+div.message div.stat {
+    font-size: 10px;
+    color: white;
+    background: green;
+    font-weight: bold;
+}
diff --git a/test/fixtures/messages.yml b/test/fixtures/messages.yml
new file mode 100644
--- /dev/null
+++ b/test/fixtures/messages.yml
@@ -0,0 +1,7 @@
+# Read about fixtures at http://ar.rubyonrails.org/classes/Fixtures.html
+
+# one:
+#   column: value
+#
+# two:
+#   column: value
diff --git a/test/functional/messages_controller_test.rb b/test/functional/messages_controller_test.rb
new file mode 100644
--- /dev/null
+++ b/test/functional/messages_controller_test.rb
@@ -0,0 +1,8 @@
+require File.dirname(__FILE__) + '/../test_helper'
+
+class MessagesControllerTest < ActionController::TestCase
+  # Replace this with your real tests.
+  def test_truth
+    assert true
+  end
+end
diff --git a/test/unit/message_test.rb b/test/unit/message_test.rb
new file mode 100644
--- /dev/null
+++ b/test/unit/message_test.rb
@@ -0,0 +1,8 @@
+require File.dirname(__FILE__) + '/../test_helper'
+
+class MessageTest < ActiveSupport::TestCase
+  # Replace this with your real tests.
+  def test_truth
+    assert true
+  end
+end