diff --git a/config.cc b/config.cc
index 354e81d0..4c1033b8 100644
--- a/config.cc
+++ b/config.cc
@@ -122,6 +122,7 @@ Preferences::Preferences():
   enableWebPlugins( false ),
   hideGoldenDictHeader( false ),
   zoomFactor( 1 ),
+  helpZoomFactor( 1 ),
   wordsZoomLevel( 0 ),
   maxStringsInHistory( 500 ),
   storeHistory( 1 ),
@@ -707,6 +708,9 @@ Class load() throw( exError )
     if ( !preferences.namedItem( "zoomFactor" ).isNull() )
       c.preferences.zoomFactor = preferences.namedItem( "zoomFactor" ).toElement().text().toDouble();
 
+    if ( !preferences.namedItem( "helpZoomFactor" ).isNull() )
+      c.preferences.helpZoomFactor = preferences.namedItem( "helpZoomFactor" ).toElement().text().toDouble();
+
     if ( !preferences.namedItem( "wordsZoomLevel" ).isNull() )
       c.preferences.wordsZoomLevel = preferences.namedItem( "wordsZoomLevel" ).toElement().text().toInt();
 
@@ -866,6 +870,16 @@ Class load() throw( exError )
   if ( !mainWindowGeometry.isNull() )
     c.mainWindowGeometry = QByteArray::fromBase64( mainWindowGeometry.toElement().text().toLatin1() );
 
+  QDomNode helpWindowGeometry = root.namedItem( "helpWindowGeometry" );
+
+  if ( !helpWindowGeometry.isNull() )
+    c.helpWindowGeometry = QByteArray::fromBase64( helpWindowGeometry.toElement().text().toLatin1() );
+
+  QDomNode helpSplitterState = root.namedItem( "helpSplitterState" );
+
+  if ( !helpSplitterState.isNull() )
+    c.helpSplitterState = QByteArray::fromBase64( helpSplitterState.toElement().text().toLatin1() );
+
 #ifdef Q_OS_WIN
   QDomNode maximizedMainWindowGeometry = root.namedItem( "maximizedMainWindowGeometry" );
 
@@ -1480,6 +1494,10 @@ void save( Class const & c ) throw( exError )
     opt.appendChild( dd.createTextNode( QString::number( c.preferences.zoomFactor ) ) );
     preferences.appendChild( opt );
 
+    opt = dd.createElement( "helpZoomFactor" );
+    opt.appendChild( dd.createTextNode( QString::number( c.preferences.helpZoomFactor ) ) );
+    preferences.appendChild( opt );
+
     opt = dd.createElement( "wordsZoomLevel" );
     opt.appendChild( dd.createTextNode( QString::number( c.preferences.wordsZoomLevel ) ) );
     preferences.appendChild( opt );
@@ -1738,6 +1756,14 @@ void save( Class const & c ) throw( exError )
     opt.appendChild( dd.createTextNode( QString::fromLatin1( c.mainWindowGeometry.toBase64() ) ) );
     root.appendChild( opt );
 
+    opt = dd.createElement( "helpWindowGeometry" );
+    opt.appendChild( dd.createTextNode( QString::fromLatin1( c.helpWindowGeometry.toBase64() ) ) );
+    root.appendChild( opt );
+
+    opt = dd.createElement( "helpSplitterState" );
+    opt.appendChild( dd.createTextNode( QString::fromLatin1( c.helpSplitterState.toBase64() ) ) );
+    root.appendChild( opt );
+
 #ifdef Q_OS_WIN
     {
       QDomElement maximizedMainWindowGeometry = dd.createElement( "maximizedMainWindowGeometry" );
diff --git a/config.hh b/config.hh
index ac24c616..81cf7784 100644
--- a/config.hh
+++ b/config.hh
@@ -225,6 +225,7 @@ struct Preferences
   bool hideGoldenDictHeader;
 
   qreal zoomFactor;
+  qreal helpZoomFactor;
   int wordsZoomLevel;
 
   unsigned maxStringsInHistory;
@@ -520,6 +521,8 @@ struct Class
   QByteArray popupWindowGeometry; // Geometry saved by QMainWindow
   QByteArray dictInfoGeometry; // Geometry of "Dictionary info" window
   QByteArray inspectorGeometry; // Geometry of WebKit inspector window
+  QByteArray helpWindowGeometry; // Geometry of help window
+  QByteArray helpSplitterState; // Geometry of help splitter
 
   QString historyExportPath; // Path for export/import history
   QString resourceSavePath;  // Path to save images/audio
diff --git a/goldendict.pro b/goldendict.pro
index 9c5d1d68..3ec7d034 100644
--- a/goldendict.pro
+++ b/goldendict.pro
@@ -20,9 +20,11 @@ QT += webkit
 QT += xml
 QT += network
 QT += svg
+QT += sql
 CONFIG += exceptions \
     rtti \
-    stl
+    stl \
+    help
 OBJECTS_DIR = build
 UI_DIR = build
 MOC_DIR = build
@@ -139,6 +141,9 @@ unix:!mac {
     desktops.path = $$PREFIX/share/applications
     desktops.files = redist/*.desktop
     INSTALLS += desktops
+    helps.path = $$PREFIX/share/goldendict/help/
+    helps.files = help/*.qch
+    INSTALLS += helps
 }
 mac {
     TARGET = GoldenDict
@@ -171,7 +176,9 @@ mac {
     QMAKE_POST_LINK = mkdir -p GoldenDict.app/Contents/Frameworks & \
                       cp -nR $${PWD}/maclibs/lib/ GoldenDict.app/Contents/Frameworks/ & \
                       mkdir -p GoldenDict.app/Contents/MacOS/locale & \
-                      cp -R locale/*.qm GoldenDict.app/Contents/MacOS/locale/
+                      cp -R locale/*.qm GoldenDict.app/Contents/MacOS/locale/ & \
+                      mkdir -p GoldenDict.app/Contents/MacOS/help & \
+                      cp -R help/*.qch GoldenDict.app/Contents/MacOS/help/
 
     CONFIG += zim_support
 }
@@ -285,7 +292,8 @@ HEADERS += folding.hh \
     dictheadwords.hh \
     fulltextsearch.hh \
     ftshelpers.hh \
-    dictserver.hh
+    dictserver.hh \
+    helpwindow.hh
 
 FORMS += groups.ui \
     dictgroupwidget.ui \
@@ -405,7 +413,8 @@ SOURCES += folding.cc \
     dictheadwords.cc \
     fulltextsearch.cc \
     ftshelpers.cc \
-    dictserver.cc
+    dictserver.cc \
+    helpwindow.cc
 
 win32 {
 	FORMS   += texttospeechsource.ui
diff --git a/help/gdhelp_en.qch b/help/gdhelp_en.qch
new file mode 100644
index 00000000..034da710
Binary files /dev/null and b/help/gdhelp_en.qch differ
diff --git a/help/gdhelp_ru.qch b/help/gdhelp_ru.qch
new file mode 100644
index 00000000..528a836b
Binary files /dev/null and b/help/gdhelp_ru.qch differ
diff --git a/helpwindow.cc b/helpwindow.cc
new file mode 100644
index 00000000..14cfb084
--- /dev/null
+++ b/helpwindow.cc
@@ -0,0 +1,252 @@
+/* This file is (c) 2014 Abs62
+ * Part of GoldenDict. Licensed under GPLv3 or later, see the LICENSE file */
+
+#include <QDir>
+#include <QFileInfo>
+#include <QSplitter>
+#include <QHelpContentWidget>
+#include <QHelpIndexWidget>
+#include <QLayout>
+#include <QDesktopServices>
+
+#include "helpwindow.hh"
+#include "gddebug.hh"
+
+namespace Help {
+
+HelpBrowser::HelpBrowser( QHelpEngineCore * engine, QWidget *parent ) :
+    QTextBrowser( parent ),
+    helpEngine( engine )
+{
+  connect( this, SIGNAL( anchorClicked( QUrl ) ), this, SLOT( linkClicked( QUrl ) ) );
+}
+
+void HelpBrowser::showHelpForKeyword( QString const & id )
+{
+  if ( helpEngine )
+  {
+    QMap< QString, QUrl > links = helpEngine->linksForIdentifier( id );
+    if( !links.isEmpty() )
+      setSource( links.constBegin().value() );
+  }
+}
+
+QVariant HelpBrowser::loadResource( int type, QUrl const & name )
+{
+  QByteArray ba;
+  if( type < 4 && helpEngine )
+  {
+    QUrl url(name);
+    if( name.isRelative() )
+      url = source().resolved( url );
+
+     ba = helpEngine->fileData(url );
+   }
+   return ba;
+}
+
+void HelpBrowser::linkClicked( QUrl const & url )
+{
+  if( url.scheme() == "http" || url.scheme() == "https" )
+  {
+    QDesktopServices::openUrl( url );
+  }
+  else
+    setSource( url );
+}
+
+HelpWindow::HelpWindow( QWidget * parent, Config::Class & cfg_ ) :
+  QDialog( parent ),
+  cfg( cfg_ ),
+  helpEngine( 0 )
+{
+  resize( QSize( 600, 450 ) );
+  setWindowTitle( tr( "GoldenDict help" ) );
+  setWindowFlags( windowFlags() & ~Qt::WindowContextHelpButtonHint );
+
+  QVBoxLayout * mainLayout = new QVBoxLayout( this );
+  setLayout( mainLayout );
+
+  navToolBar = new QToolBar( this );
+  navHome = navToolBar->addAction( QIcon( ":/icons/home.png" ), tr( "Home" ) );
+  navToolBar->widgetForAction( navHome )->setObjectName( "helpHomeButton" );
+  navBack = navToolBar->addAction( QIcon( ":/icons/previous.png" ), tr( "Back" ) );
+  navToolBar->widgetForAction( navBack )->setObjectName( "helpBackButton" );
+  navForward = navToolBar->addAction( QIcon( ":/icons/next.png" ), tr( "Forward" ) );
+  navToolBar->widgetForAction( navForward )->setObjectName( "helpForwardButton" );
+
+  navToolBar->addSeparator();
+
+  zoomInAction = navToolBar->addAction( QIcon( ":/icons/icon32_zoomin" ), tr( "Zoom In" ) );
+  navToolBar->widgetForAction( zoomInAction )->setObjectName( "zoomInButton" );
+  zoomOutAction = navToolBar->addAction( QIcon( ":/icons/icon32_zoomout" ), tr( "Zoom Out" ) );
+  navToolBar->widgetForAction( zoomInAction )->setObjectName( "zoomOutButton" );
+  zoomBaseAction = navToolBar->addAction( QIcon( ":/icons/icon32_zoombase" ), tr( "Normal Size" ) );
+  navToolBar->widgetForAction( zoomBaseAction )->setObjectName( "zoomBaseButton" );
+
+  navForward->setEnabled( false );
+  navBack->setEnabled( false );
+
+  mainLayout->addWidget( navToolBar );
+
+  QString localeName = cfg.preferences.interfaceLanguage;
+  if( localeName.isEmpty() )
+    localeName = QLocale::system().name();
+
+  helpFile = QDir::toNativeSeparators( Config::getProgramDataDir() + "/help/gdhelp_"
+                                       + localeName.left( 2 ) + ".qch" );
+
+  if( !QFileInfo( helpFile ).isFile() )
+    helpFile = QDir::toNativeSeparators( Config::getProgramDataDir() + "/help/gdhelp_en.qch" );
+
+  helpCollectionFile = QDir::toNativeSeparators( Config::getConfigDir() + "gdhelp.qhc" );
+
+  helpEngine = new QHelpEngine( helpCollectionFile );
+
+  if( !helpEngine->setupData() )
+  {
+    gdWarning( "Help engine initialization error: %s", helpEngine->error().toUtf8().data() );
+    delete helpEngine;
+    helpEngine = 0;
+  }
+  else
+  {
+    if( !helpEngine->registerDocumentation( helpFile ) )
+    {
+      gdWarning( "Help engine set file error: %s", helpEngine->error().toUtf8().data() );
+    }
+
+    tabWidget = new QTabWidget( this );
+    tabWidget->addTab( helpEngine->contentWidget(), tr( "Content" ) );
+    tabWidget->addTab( helpEngine->indexWidget(), tr( "Index" ) );
+
+    helpBrowser = new HelpBrowser( helpEngine, this );
+
+    helpBrowser->setOpenLinks( false );
+
+    connect( helpEngine->contentWidget(), SIGNAL( linkActivated( QUrl ) ),
+             helpBrowser, SLOT( setSource( QUrl ) ) );
+    connect( helpEngine->indexWidget(), SIGNAL( linkActivated( QUrl, QString ) ),
+             helpBrowser, SLOT( setSource( QUrl ) ) );
+
+    connect( navHome, SIGNAL( triggered() ), helpBrowser, SLOT( home() ) );
+    connect( navForward, SIGNAL( triggered() ), helpBrowser, SLOT( forward() ) );
+    connect( navBack, SIGNAL( triggered() ), helpBrowser, SLOT( backward() ) );
+
+    connect( helpBrowser, SIGNAL( forwardAvailable( bool ) ),
+             this, SLOT( forwardEnabled( bool ) ) );
+
+    connect( helpBrowser, SIGNAL( backwardAvailable( bool ) ),
+             this, SLOT( backwardEnabled( bool ) ) );
+
+    connect( helpEngine->contentWidget(), SIGNAL( clicked( QModelIndex ) ),
+             this, SLOT( contentsItemClicked( QModelIndex ) ) );
+
+    connect( zoomInAction, SIGNAL( triggered( ) ), this, SLOT( zoomIn() ) );
+    connect( zoomOutAction, SIGNAL( triggered( ) ), this, SLOT( zoomOut() ) );
+    connect( zoomBaseAction, SIGNAL( triggered( ) ), this, SLOT( zoomBase() ) );
+
+    splitter = new QSplitter( this );
+    splitter->addWidget( tabWidget );
+    splitter->addWidget( helpBrowser );
+
+    splitter->setStretchFactor( 0, 1 );
+    splitter->setStretchFactor( 1, 4 );
+    mainLayout->addWidget( splitter );
+  }
+
+  if( !cfg.helpWindowGeometry.isEmpty() )
+    restoreGeometry( cfg.helpWindowGeometry );
+  if( !cfg.helpSplitterState.isEmpty() )
+    splitter->restoreState( cfg.helpSplitterState );
+
+  QFont f = helpBrowser->font();
+  fontSize = f.pointSize();
+  if( fontSize < 10 )
+  {
+    fontSize = 10;
+    f.setPointSize( fontSize );
+    helpBrowser->setFont( f );
+  }
+
+  applyZoomFactor();
+}
+
+HelpWindow::~HelpWindow()
+{
+  if( helpEngine )
+    delete helpEngine;
+
+  QFile f( helpCollectionFile );
+  f.remove();
+}
+
+void HelpWindow::reject()
+{
+  cfg.helpWindowGeometry = saveGeometry();
+  cfg.helpSplitterState = splitter->saveState();
+  emit needClose();
+}
+
+void HelpWindow::accept()
+{
+  cfg.helpWindowGeometry = saveGeometry();
+  cfg.helpSplitterState = splitter->saveState();
+  emit needClose();
+}
+
+void HelpWindow::forwardEnabled( bool enabled )
+{
+  navForward->setEnabled( enabled );
+}
+
+void HelpWindow::backwardEnabled( bool enabled )
+{
+  navBack->setEnabled( enabled );
+}
+
+void HelpWindow::contentsItemClicked( QModelIndex const & index )
+{
+  QHelpContentItem * item = helpEngine->contentModel()->contentItemAt( index );
+  if( !item->url().isEmpty() )
+    helpBrowser->setSource( item->url() );
+}
+
+void HelpWindow::zoomIn()
+{
+  cfg.preferences.helpZoomFactor += 0.2;
+  applyZoomFactor();
+}
+
+void HelpWindow::zoomOut()
+{
+  cfg.preferences.helpZoomFactor -= 0.2;
+  applyZoomFactor();
+}
+
+void HelpWindow::zoomBase()
+{
+  cfg.preferences.helpZoomFactor = 1;
+  applyZoomFactor();
+}
+
+void HelpWindow::applyZoomFactor()
+{
+  if ( cfg.preferences.helpZoomFactor >= 5 )
+    cfg.preferences.helpZoomFactor = 5;
+  else if ( cfg.preferences.helpZoomFactor <= 0.2 )
+    cfg.preferences.helpZoomFactor = 0.2;
+
+  zoomInAction->setEnabled( cfg.preferences.helpZoomFactor < 5 );
+  zoomOutAction->setEnabled( cfg.preferences.helpZoomFactor > 0.2 );
+  zoomBaseAction->setEnabled( cfg.preferences.helpZoomFactor != 1.0 );
+
+  if( fontSize > 0 )
+  {
+    QFont f = helpBrowser->font();
+    f.setPointSize( fontSize * cfg.preferences.helpZoomFactor );
+    helpBrowser->setFont( f );
+  }
+}
+
+} // namespace Help
diff --git a/helpwindow.hh b/helpwindow.hh
new file mode 100644
index 00000000..fcfb2d2d
--- /dev/null
+++ b/helpwindow.hh
@@ -0,0 +1,77 @@
+#ifndef __HELPWINDOW_HH_INCLUDED__
+#define __HELPWINDOW_HH_INCLUDED__
+
+#include <QDialog>
+#include <QToolBar>
+#include <QtHelp/QHelpEngine>
+#include <QString>
+#include <QTextBrowser>
+#include <QTableWidget>
+#include <QAction>
+#include <QSplitter>
+
+#include <exception>
+
+#include "config.hh"
+
+namespace Help {
+
+class HelpBrowser : public QTextBrowser
+{
+Q_OBJECT
+public:
+  HelpBrowser( QHelpEngineCore * engine, QWidget *parent );
+  void showHelpForKeyword( QString const & id );
+private:
+  QVariant loadResource( int type, QUrl const & name );
+  QHelpEngineCore * helpEngine;
+
+private slots:
+  void linkClicked( QUrl const & url );
+};
+
+
+class HelpWindow : public QDialog
+{
+Q_OBJECT
+
+  Config::Class & cfg;
+  QToolBar * navToolBar;
+  QHelpEngine * helpEngine;
+  QTabWidget * tabWidget;
+  HelpBrowser * helpBrowser;
+  QAction * navForward, * navBack, * navHome;
+  QAction * zoomInAction, * zoomOutAction, * zoomBaseAction;
+  QSplitter * splitter;
+
+  QString helpFile, helpCollectionFile;
+
+  int fontSize;
+
+  void applyZoomFactor();
+
+public:
+  HelpWindow( QWidget * parent, Config::Class & cfg_ );
+  ~HelpWindow();
+
+  QHelpEngine const * getHelpEngine()
+  { return helpEngine; }
+
+public slots:
+  virtual void reject();
+  virtual void accept();
+  void forwardEnabled( bool enabled );
+  void backwardEnabled( bool enabled );
+  void contentsItemClicked( QModelIndex const & index );
+
+  void zoomIn();
+  void zoomOut();
+  void zoomBase();
+
+signals:
+  void needClose();
+};
+
+} // namespace Help
+
+#endif // __HELPWINDOW_HH_INCLUDED__
diff --git a/icons/home.png b/icons/home.png
new file mode 100644
index 00000000..b1c6ae19
Binary files /dev/null and b/icons/home.png differ
diff --git a/mainwindow.cc b/mainwindow.cc
index d8f3c8a0..d2b08398 100644
--- a/mainwindow.cc
+++ b/mainwindow.cc
@@ -116,6 +116,7 @@ MainWindow::MainWindow( Config::Class & cfg_ ):
 , headwordsDlg( 0 )
 , ftsIndexing( dictionaries )
 , ftsDlg( 0 )
+, helpWindow( 0 )
 #ifdef Q_OS_WIN32
 , gdAskMessage( 0xFFFFFFFF )
 #endif
@@ -610,6 +611,8 @@ MainWindow::MainWindow( Config::Class & cfg_ ):
            this, SLOT( openConfigFolder() ) );
   connect( ui.about, SIGNAL( triggered() ),
            this, SLOT( showAbout() ) );
+  connect( ui.showReference, SIGNAL( triggered() ),
+           this, SLOT( showGDHelp() ) );
 
   connect( groupListInDock, SIGNAL( currentIndexChanged( QString const & ) ),
            this, SLOT( currentGroupChanged( QString const & ) ) );
@@ -1900,6 +1903,7 @@ void MainWindow::editPreferences()
 
     // These parameters are not set in dialog
     p.zoomFactor = cfg.preferences.zoomFactor;
+    p.helpZoomFactor = cfg.preferences.helpZoomFactor;
     p.wordsZoomLevel = cfg.preferences.wordsZoomLevel;
     p.hideMenubar = cfg.preferences.hideMenubar;
     p.searchInDock = cfg.preferences.searchInDock;
@@ -2702,6 +2706,9 @@ void MainWindow::toggleMainWindow( bool onlyShow )
 
     if( ftsDlg )
       ftsDlg->hide();
+
+    if( helpWindow )
+      helpWindow->hide();
   }
 
   if ( shown )
@@ -4039,6 +4046,29 @@ void MainWindow::closeFullTextSearchDialog()
   }
 }
 
+void MainWindow::showGDHelp()
+{
+  if( !helpWindow )
+    helpWindow = new Help::HelpWindow( this, cfg );
+
+  if( helpWindow->getHelpEngine() )
+  {
+    connect( helpWindow, SIGNAL( needClose() ), this, SLOT( hideGDHelp() ) );
+    helpWindow->show();
+  }
+  else
+  {
+    delete helpWindow;
+    helpWindow = 0;
+  }
+}
+
+void MainWindow::hideGDHelp()
+{
+  if( helpWindow )
+    helpWindow->hide();
+}
+
 #ifdef Q_OS_WIN32
 
 bool MainWindow::handleGDMessage( MSG * message, long * result )
diff --git a/mainwindow.hh b/mainwindow.hh
index f94bc270..1fd33704 100644
--- a/mainwindow.hh
+++ b/mainwindow.hh
@@ -29,6 +29,7 @@
 #include "wordlist.hh"
 #include "dictheadwords.hh"
 #include "fulltextsearch.hh"
+#include "helpwindow.hh"
 
 #ifdef Q_WS_X11
 #include <fixx11h.h>
@@ -168,6 +169,8 @@ private:
 
   FTS::FullTextSearchDialog * ftsDlg;
 
+  Help::HelpWindow * helpWindow;
+
   /// Applies the qt's stylesheet, given the style's name.
   void applyQtStyleSheet( QString const & displayStyle, QString const & addonStyle );
 
@@ -427,6 +430,9 @@ private slots:
   void showFullTextSearchDialog();
   void closeFullTextSearchDialog();
 
+  void showGDHelp();
+  void hideGDHelp();
+
 signals:
   /// Set optional parts expand mode for all tabs
   void setExpandOptionalParts( bool expand );
diff --git a/mainwindow.ui b/mainwindow.ui
index 7c15d613..71ba3540 100644
--- a/mainwindow.ui
+++ b/mainwindow.ui
@@ -101,6 +101,8 @@
     <property name="title">
      <string>&amp;Help</string>
     </property>
+    <addaction name="showReference"/>
+    <addaction name="separator"/>
     <addaction name="visitHomepage"/>
     <addaction name="visitForum"/>
     <addaction name="separator"/>
@@ -372,9 +374,6 @@
    <property name="toolTip">
     <string>About GoldenDict</string>
    </property>
-   <property name="shortcut">
-    <string>F1</string>
-   </property>
    <property name="menuRole">
     <enum>QAction::AboutRole</enum>
    </property>
@@ -587,6 +586,14 @@
     <enum>QAction::TextHeuristicRole</enum>
    </property>
   </action>
+  <action name="showReference">
+   <property name="text">
+    <string>GoldenDict reference</string>
+   </property>
+   <property name="shortcut">
+    <string>F1</string>
+   </property>
+  </action>
  </widget>
  <customwidgets>
   <customwidget>
diff --git a/resources.qrc b/resources.qrc
index 8e9760cb..cc29474e 100644
--- a/resources.qrc
+++ b/resources.qrc
@@ -10,6 +10,7 @@
         <file>icons/addtab.png</file>
         <file>icons/next.png</file>
         <file>icons/previous.png</file>
+        <file>icons/home.png</file>
         <file>icons/reload.png</file>
         <file>icons/programicon.png</file>
         <file>icons/programicon_scan.png</file>