diff --git a/src/xdxf.cc b/src/xdxf.cc
new file mode 100644
index 00000000..4d0e2b4f
--- /dev/null
+++ b/src/xdxf.cc
@@ -0,0 +1,812 @@
+/* This file is (c) 2008-2009 Konstantin Isakov <ikm@users.berlios.de>
+ * Part of GoldenDict. Licensed under GPLv3 or later, see the LICENSE file */
+
+#include "xdxf.hh"
+#include "btreeidx.hh"
+#include "folding.hh"
+#include "utf8.hh"
+#include "chunkedstorage.hh"
+#include "dictzip.h"
+#include "htmlescape.hh"
+#include "fsencoding.hh"
+#include <map>
+#include <set>
+#include <string>
+#include <vector>
+#include <list>
+#include <zlib.h>
+#include <wctype.h>
+#include <stdlib.h>
+
+#include <QIODevice>
+#include <QXmlStreamReader>
+#include <QTextDocument>
+
+#include <QSemaphore>
+#include <QThreadPool>
+#include <QAtomicInt>
+
+namespace Xdxf {
+
+using std::map;
+using std::multimap;
+using std::pair;
+using std::set;
+using std::string;
+using gd::wstring;
+using std::vector;
+using std::list;
+
+using BtreeIndexing::WordArticleLink;
+using BtreeIndexing::IndexedWords;
+using BtreeIndexing::IndexInfo;
+
+namespace {
+
+DEF_EX_STR( exCantReadFile, "Can't read file", Dictionary::Ex )
+DEF_EX_STR( exNotXdxfFile, "The file is not an XDXF file:", Dictionary::Ex )
+DEF_EX( exCorruptedIndex, "The index file is corrupted", Dictionary::Ex )
+
+enum
+{
+  Signature = 0x46584458, // XDXF on little-endian, FXDX on big-endian
+  CurrentFormatVersion = 1 + BtreeIndexing::FormatVersion + Folding::Version
+};
+
+enum ArticleFormat
+{
+  Default = 0,
+  Visual = 1,
+  Logical = 2
+};
+
+struct IdxHeader
+{
+  uint32_t signature; // First comes the signature, XDXF
+  uint32_t formatVersion; // File format version (CurrentFormatVersion)
+  uint32_t articleFormat; // ArticleFormat value, except that 0 = bad file
+  char fromLang[ 4 ]; // 3-letter ISO-639.2 language code
+  char toLang[ 4 ]; // 3-letter ISO-639.2 language code
+  uint32_t articleCount; // Total number of articles
+  uint32_t wordCount; // Total number of words
+  uint32_t nameAddress; // Address of an utf8 name string, in chunks
+  uint32_t nameSize; // And its size
+  uint32_t descriptionAddress; // Address of an utf8 description string, in chunks
+  uint32_t descriptionSize; // And its size
+  uint32_t abbreviationsCount; // Number of abbreviations
+  uint32_t chunksOffset; // The offset to chunks' storage
+  uint32_t indexBtreeMaxElements; // Two fields from IndexInfo
+  uint32_t indexRootOffset;
+} __attribute__((packed));
+
+bool indexIsOldOrBad( string const & indexFile )
+{
+  File::Class idx( indexFile, "rb" );
+
+  IdxHeader header;
+
+  return idx.readRecords( &header, sizeof( header ), 1 ) != 1 ||
+         header.signature != Signature ||
+         header.formatVersion != CurrentFormatVersion ||
+         !header.articleFormat;
+}
+
+
+
+class XdxfDictionary: public BtreeIndexing::BtreeDictionary
+{
+  Mutex idxMutex;
+  File::Class idx;
+  IdxHeader idxHeader;
+  ChunkedStorage::Reader chunks;
+  Mutex dzMutex;
+  dictData * dz;
+  string dictionaryName;
+
+public:
+
+  XdxfDictionary( string const & id, string const & indexFile,
+                   vector< string > const & dictionaryFiles );
+
+  ~XdxfDictionary();
+
+  virtual string getName() throw()
+  { return dictionaryName; }
+
+  virtual map< Dictionary::Property, string > getProperties() throw()
+  { return map< Dictionary::Property, string >(); }
+
+  virtual unsigned long getArticleCount() throw()
+  { return idxHeader.wordCount; }
+
+  virtual unsigned long getWordCount() throw()
+  { return idxHeader.wordCount; }
+
+  virtual QIcon getIcon() throw()
+  { return QIcon(":/icons/icon32_xdxf.png"); }
+
+  virtual sptr< Dictionary::DataRequest > getArticle( wstring const &,
+                                                      vector< wstring > const & alts )
+    throw( std::exception );
+
+private:
+
+  /// Loads the article, storing its headword and formatting the data it has
+  /// into an html.
+  void loadArticle( uint32_t address,
+                    string & headword,
+                    string & articleText );
+
+  friend class XdxfArticleRequest;
+};
+
+XdxfDictionary::XdxfDictionary( string const & id,
+                                string const & indexFile,
+                                vector< string > const & dictionaryFiles ):
+  BtreeDictionary( id, dictionaryFiles ),
+  idx( indexFile, "rb" ),
+  idxHeader( idx.read< IdxHeader >() ),
+  chunks( idx, idxHeader.chunksOffset )
+{
+  // Read the dictionary name
+
+  if ( idxHeader.nameSize )
+  {
+    vector< char > chunk;
+
+    dictionaryName = string( chunks.getBlock( idxHeader.nameAddress, chunk ),
+                             idxHeader.nameSize );
+  }
+
+  // Open the file
+
+  dz = dict_data_open( dictionaryFiles[ 0 ].c_str(), 0 );
+
+  if ( !dz )
+    throw exCantReadFile( dictionaryFiles[ 0 ] );
+
+  // Initialize the index
+
+  openIndex( IndexInfo( idxHeader.indexBtreeMaxElements,
+                        idxHeader.indexRootOffset ),
+             idx, idxMutex );
+}
+
+XdxfDictionary::~XdxfDictionary()
+{
+  if ( dz )
+    dict_data_close( dz );
+}
+
+/// XdxfDictionary::getArticle()
+
+class XdxfArticleRequest;
+
+class XdxfArticleRequestRunnable: public QRunnable
+{
+  XdxfArticleRequest & r;
+  QSemaphore & hasExited;
+
+public:
+
+  XdxfArticleRequestRunnable( XdxfArticleRequest & r_,
+                                  QSemaphore & hasExited_ ): r( r_ ),
+                                                             hasExited( hasExited_ )
+  {}
+
+  ~XdxfArticleRequestRunnable()
+  {
+    hasExited.release();
+  }
+
+  virtual void run();
+};
+
+class XdxfArticleRequest: public Dictionary::DataRequest
+{
+  friend class XdxfArticleRequestRunnable;
+
+  wstring word;
+  vector< wstring > alts;
+  XdxfDictionary & dict;
+
+  QAtomicInt isCancelled;
+  QSemaphore hasExited;
+
+public:
+
+  XdxfArticleRequest( wstring const & word_,
+                     vector< wstring > const & alts_,
+                     XdxfDictionary & dict_ ):
+    word( word_ ), alts( alts_ ), dict( dict_ )
+  {
+    QThreadPool::globalInstance()->start(
+      new XdxfArticleRequestRunnable( *this, hasExited ) );
+  }
+
+  void run(); // Run from another thread by XdxfArticleRequestRunnable
+
+  virtual void cancel()
+  {
+    isCancelled.ref();
+  }
+
+  ~XdxfArticleRequest()
+  {
+    isCancelled.ref();
+    hasExited.acquire();
+  }
+};
+
+void XdxfArticleRequestRunnable::run()
+{
+  r.run();
+}
+
+void XdxfArticleRequest::run()
+{
+  if ( isCancelled )
+  {
+    finish();
+    return;
+  }
+
+  vector< WordArticleLink > chain = dict.findArticles( word );
+
+  for( unsigned x = 0; x < alts.size(); ++x )
+  {
+    /// Make an additional query for each alt
+
+    vector< WordArticleLink > altChain = dict.findArticles( alts[ x ] );
+
+    chain.insert( chain.end(), altChain.begin(), altChain.end() );
+  }
+
+  multimap< wstring, pair< string, string > > mainArticles, alternateArticles;
+
+  set< uint32_t > articlesIncluded; // Some synonims make it that the articles
+                                    // appear several times. We combat this
+                                    // by only allowing them to appear once.
+
+  wstring wordCaseFolded = Folding::applySimpleCaseOnly( word );
+
+  for( unsigned x = 0; x < chain.size(); ++x )
+  {
+    if ( isCancelled )
+    {
+      finish();
+      return;
+    }
+
+    if ( articlesIncluded.find( chain[ x ].articleOffset ) != articlesIncluded.end() )
+      continue; // We already have this article in the body.
+
+    // Now grab that article
+
+    string headword, articleText;
+
+    dict.loadArticle( chain[ x ].articleOffset, headword, articleText );
+
+    // Ok. Now, does it go to main articles, or to alternate ones? We list
+    // main ones first, and alternates after.
+
+    // We do the case-folded comparison here.
+
+    wstring headwordStripped =
+      Folding::applySimpleCaseOnly( Utf8::decode( headword ) );
+
+    multimap< wstring, pair< string, string > > & mapToUse =
+      ( wordCaseFolded == headwordStripped ) ?
+        mainArticles : alternateArticles;
+
+    mapToUse.insert( pair< wstring, pair< string, string > >(
+      Folding::applySimpleCaseOnly( Utf8::decode( headword ) ),
+      pair< string, string >( headword, articleText ) ) );
+
+    articlesIncluded.insert( chain[ x ].articleOffset );
+  }
+
+  if ( mainArticles.empty() && alternateArticles.empty() )
+  {
+    // No such word
+    finish();
+    return;
+  }
+
+  string result;
+
+  multimap< wstring, pair< string, string > >::const_iterator i;
+
+  string cleaner = "</font>""</font>""</font>""</font>""</font>""</font>"
+                   "</font>""</font>""</font>""</font>""</font>""</font>"
+                   "</b></b></b></b></b></b></b></b>"
+                   "</i></i></i></i></i></i></i></i>";
+
+  for( i = mainArticles.begin(); i != mainArticles.end(); ++i )
+  {
+      result += "<h3>";
+      result += i->second.first;
+      result += "</h3>";
+      result += i->second.second;
+      result += cleaner;
+  }
+
+  for( i = alternateArticles.begin(); i != alternateArticles.end(); ++i )
+  {
+      result += "<h3>";
+      result += i->second.first;
+      result += "</h3>";
+      result += i->second.second;
+      result += cleaner;
+  }
+
+  Mutex::Lock _( dataMutex );
+
+  data.resize( result.size() );
+
+  memcpy( &data.front(), result.data(), result.size() );
+
+  hasAnyData = true;
+
+  finish();
+}
+
+sptr< Dictionary::DataRequest > XdxfDictionary::getArticle( wstring const & word,
+                                                            vector< wstring > const & alts )
+  throw( std::exception )
+{
+  return new XdxfArticleRequest( word, alts, *this );
+}
+
+void XdxfDictionary::loadArticle( uint32_t address,
+                                  string & headword,
+                                  string & articleText )
+{
+  // Read the properties
+
+  vector< char > chunk;
+
+  char * propertiesData;
+
+  {
+    Mutex::Lock _( idxMutex );
+  
+    propertiesData = chunks.getBlock( address, chunk );
+  }
+
+  if ( &chunk.front() + chunk.size() - propertiesData < 9 )
+    throw exCorruptedIndex();
+
+  unsigned char fType = (unsigned char) *propertiesData;
+
+  uint32_t articleOffset, articleSize;
+
+  memcpy( &articleOffset, propertiesData + 1, sizeof( uint32_t ) );
+  memcpy( &articleSize, propertiesData + 5, sizeof( uint32_t ) );
+
+  // Load the article
+
+  char * articleBody;
+
+  {
+    Mutex::Lock _( dzMutex );
+
+    // Note that the function always zero-pads the result.
+    articleBody = dict_data_read_( dz, articleOffset, articleSize, 0, 0 );
+  }
+
+  if ( !articleBody )
+    throw exCantReadFile( getDictionaryFilenames()[ 0 ] );
+
+  articleText = Html::escape( articleBody );
+
+  headword = "foo";
+
+  free( articleBody );
+}
+
+class GzippedFile: public QIODevice
+{
+  gzFile gz;
+
+public:
+
+  GzippedFile( char const * fileName ) throw( exCantReadFile );
+
+  ~GzippedFile();
+
+  size_t gzTell();
+
+protected:
+
+  virtual bool isSequential () const
+  { return false; } // Which is a lie, but else pos() won't work
+
+  bool waitForReadyRead ( int )
+  { return !gzeof( gz ); }
+
+ qint64 bytesAvailable() const
+ {
+     return ( gzeof( gz ) ? 0 : 1 ) + QIODevice::bytesAvailable();
+ }
+
+  virtual qint64 readData( char * data, qint64 maxSize );
+
+  virtual bool atEnd();
+
+  virtual qint64 writeData ( const char * /*data*/, qint64 /*maxSize*/ )
+  { return -1; }
+};
+
+GzippedFile::GzippedFile( char const * fileName ) throw( exCantReadFile )
+{
+  gz = gzopen( fileName, "rb" );
+
+  if ( !gz )
+    throw exCantReadFile( fileName );
+}
+
+GzippedFile::~GzippedFile()
+{
+  gzclose( gz );
+}
+
+bool GzippedFile::atEnd()
+{
+  return gzeof( gz );
+}
+
+size_t GzippedFile::gzTell()
+{
+  return gztell( gz );
+}
+
+qint64 GzippedFile::readData( char * data, qint64 maxSize )
+{
+  if ( maxSize > 1 )
+    maxSize = 1;
+
+  // The returning value translates directly to QIODevice semantics
+  return gzread( gz, data, maxSize );
+}
+
+QString readXhtmlData( QXmlStreamReader & stream )
+{
+  QString result;
+
+  while( !stream.atEnd() )
+  {
+    stream.readNext();
+
+    if ( stream.isStartElement() )
+    {
+      QString name = stream.name().toString();
+
+      result += "<" + Qt::escape( name ) + " ";
+
+      QXmlStreamAttributes attrs = stream.attributes();
+
+      for( int x = 0; x < attrs.size(); ++x )
+      {
+        result += Qt::escape( attrs[ x ].name().toString() );
+        result += "=\"" + Qt::escape( attrs[ x ].value().toString() ) + "\"";
+      }
+
+      result += ">";
+
+      result += readXhtmlData( stream );
+
+      result += "</" + Qt::escape( name ) + ">";
+    }
+    else
+    if ( stream.isCharacters() || stream.isWhitespace() || stream.isCDATA() )
+    {
+      result += stream.text();
+    }
+    else
+    if ( stream.isEndElement() )
+      break;
+  }
+
+  return result;
+}
+
+void addAllKeyTags( QXmlStreamReader & stream, list< QString > & words )
+{
+  if ( stream.name() == "k" )
+  {
+    words.push_back( stream.readElementText() );
+    return;
+  }
+
+  for( ; ; )
+  {
+    stream.readNext();
+  
+    if ( stream.isStartElement() )
+      addAllKeyTags( stream, words );
+    else
+    if ( stream.isEndElement() )
+      return;
+  }
+}
+
+void indexArticle( GzippedFile & gzFile,
+                   QXmlStreamReader & stream,
+                   IndexedWords & indexedWords,
+                   ChunkedStorage::Writer & chunks,
+                   unsigned & articleCount,
+                   unsigned & wordCount )
+{
+  ArticleFormat format( Default );
+
+  QStringRef formatValue = stream.attributes().value( "f" );
+
+  if ( formatValue == "v" )
+    format = Visual;
+  else
+  if ( formatValue == "l" )
+    format = Logical;
+
+  size_t articleOffset = gzFile.pos() - 1; // stream.characterOffset() is loony
+
+  uint32_t lineNumber = stream.lineNumber();
+  uint32_t columnNumber = stream.columnNumber();
+
+  list< QString > words;
+
+  while( !stream.atEnd() )
+  {
+    stream.readNext();
+
+    // Find any <k> tags and index them
+    if ( stream.isEndElement() )
+    {
+      // End of the <ar> tag
+
+      if ( words.empty() )
+      {
+        // Nothing to index, this article didn't have any tags
+        printf( "Warning: no <k> tags found in an article at offset 0x%x, article skipped.\n",
+                (unsigned) articleOffset );
+      }
+      else
+      {
+        // Add an entry
+
+        uint32_t offset = chunks.startNewBlock();
+
+        uint32_t value = articleOffset;
+
+        unsigned char f = format;
+        chunks.addToBlock( &f, 1 );
+        chunks.addToBlock( &value, sizeof( value ) );
+        value = gzFile.pos() - 1 - articleOffset;
+        chunks.addToBlock( &value, sizeof( value ) );
+
+        printf( "%x: %s\n", articleOffset, words.begin()->toUtf8().data() );
+
+        // Add words to index
+
+        for( list< QString >::const_iterator i = words.begin(); i != words.end();
+             ++i )
+          indexedWords.addWord( i->toStdWString(), offset );
+
+        ++articleCount;
+
+        wordCount += words.size();
+      }
+
+      return;
+    }
+    else
+    if ( stream.isStartElement() )
+    {
+      addAllKeyTags( stream, words );
+    }
+  }
+}
+
+} // anonymous namespace
+
+vector< sptr< Dictionary::Class > > makeDictionaries(
+                                      vector< string > const & fileNames,
+                                      string const & indicesDir,
+                                      Dictionary::Initializing & initializing )
+  throw( std::exception )
+{
+  vector< sptr< Dictionary::Class > > dictionaries;
+
+  for( vector< string >::const_iterator i = fileNames.begin(); i != fileNames.end();
+       ++i )
+  {
+    // Only allow .xdxf and .xdxf.dz suffixes
+
+    if ( ( i->size() < 5  || strcasecmp( i->c_str() + ( i->size() - 5 ), ".xdxf" ) != 0 ) &&
+         ( i->size() < 8 ||
+           strcasecmp( i->c_str() + ( i->size() - 8 ), ".xdxf.dz" ) != 0 ) )
+      continue;
+
+    try
+    {
+      vector< string > dictFiles( 1, *i );
+
+      string dictId = Dictionary::makeDictionaryId( dictFiles );
+
+      string indexFile = indicesDir + dictId;
+
+      if ( Dictionary::needToRebuildIndex( dictFiles, indexFile ) ||
+           indexIsOldOrBad( indexFile ) )
+      {
+        // Building the index
+
+        //initializing.indexingDictionary( nameFromFileName( dictFiles[ 0 ] ) );
+
+        File::Class idx( indexFile, "wb" );
+
+        IdxHeader idxHeader;
+
+        memset( &idxHeader, 0, sizeof( idxHeader ) );
+
+        // We write a dummy header first. At the end of the process the header
+        // will be rewritten with the right values.
+
+        idx.write( idxHeader );
+
+        IndexedWords indexedWords;
+
+        GzippedFile gzFile( dictFiles[ 0 ].c_str() );
+
+        if ( !gzFile.open( QIODevice::ReadOnly ) )
+          throw exCantReadFile( dictFiles[ 0 ] );
+
+        QXmlStreamReader stream( &gzFile );
+
+        QString dictionaryName, dictionaryDescription;
+
+        ChunkedStorage::Writer chunks( idx );
+
+        // Wait for the first element, which must be xdxf
+
+        bool hadXdxf = false;
+
+        while( !stream.atEnd() )
+        {
+          stream.readNext();
+
+          if ( stream.isStartElement() )
+          {
+            if ( stream.name() != "xdxf" )
+              throw exNotXdxfFile( dictFiles[ 0 ] );
+            else
+            {
+              // Read the xdxf
+
+              string str = stream.attributes().value( "lang_from" ).toString().toAscii().data();
+
+              if ( str.size() > 3 )
+                str.resize( 3 );
+
+              strcpy( idxHeader.fromLang, str.c_str() );
+
+              str = stream.attributes().value( "lang_to" ).toString().toAscii().data();
+
+              if ( str.size() > 3 )
+                str.resize( 3 );
+
+              strcpy( idxHeader.toLang, str.c_str() );
+
+              bool isLogical = ( stream.attributes().value( "format" ) == "logical" );
+
+              idxHeader.articleFormat = isLogical ? Logical : Visual;
+
+              unsigned articleCount = 0, wordCount = 0;
+
+              while( !stream.atEnd() )
+              {
+                stream.readNext();
+
+                if ( stream.isStartElement() )
+                {
+                  if ( stream.name() == "full_name" )
+                  {
+                    // That's our name
+
+                    QString name = stream.readElementText();
+
+                    if ( dictionaryName.isEmpty() )
+                    {
+                      dictionaryName = name;
+
+                      initializing.indexingDictionary( dictionaryName.toUtf8().data() );
+
+                      idxHeader.nameAddress = chunks.startNewBlock();
+
+                      QByteArray n = dictionaryName.toUtf8();
+
+                      idxHeader.nameSize = n.size();
+
+                      chunks.addToBlock( n.data(), n.size() );
+                    }
+                    else
+                      printf( "Warning: duplicate full_name in %s\n", dictFiles[ 0 ].c_str() );
+                  }
+                  else
+                  if ( stream.name() == "description" )
+                  {
+                    QString desc = readXhtmlData( stream );
+
+                    if ( dictionaryDescription.isEmpty() )
+                    {
+                      dictionaryDescription = desc;
+                      idxHeader.descriptionAddress = chunks.startNewBlock();
+
+                      QByteArray n = dictionaryDescription.toUtf8();
+
+                      idxHeader.descriptionSize = n.size();
+
+                      chunks.addToBlock( n.data(), n.size() );
+                    }
+                    else
+                      printf( "Warning: duplicate description in %s\n", dictFiles[ 0 ].c_str() );
+                  }
+                  else
+                  if ( stream.name() == "ar" )
+                  {
+                    indexArticle( gzFile, stream, indexedWords, chunks,
+                                  articleCount, wordCount );
+                  }
+                }
+              }
+
+              // Finish with the chunks
+
+              idxHeader.chunksOffset = chunks.finish();
+
+              // Build index
+
+              IndexInfo idxInfo = BtreeIndexing::buildIndex( indexedWords, idx );
+
+              idxHeader.indexBtreeMaxElements = idxInfo.btreeMaxElements;
+              idxHeader.indexRootOffset = idxInfo.rootOffset;
+
+              // That concludes it. Update the header.
+
+              idxHeader.signature = Signature;
+              idxHeader.formatVersion = CurrentFormatVersion;
+
+              idx.rewind();
+
+              idx.write( &idxHeader, sizeof( idxHeader ) );
+
+              hadXdxf = true;
+            }
+            break;
+          }
+        }
+
+        if ( !hadXdxf )
+          throw exNotXdxfFile( dictFiles[ 0 ] );
+
+        if ( stream.hasError() )
+        {
+          printf( "Warning: %s had a parse error %ls, and therefore was indexed only up to the point of error.\n",
+                  dictFiles[ 0 ].c_str(), stream.errorString().toStdWString().c_str() );
+        }
+      }
+
+      dictionaries.push_back( new XdxfDictionary( dictId,
+                                                  indexFile,
+                                                  dictFiles ) );
+    }
+    catch( std::exception & e )
+    {
+      fprintf( stderr, "Xdxf dictionary reading failed: %s, error: %s\n",
+        i->c_str(), e.what() );
+    }
+  }
+
+  return dictionaries;
+}
+
+}
diff --git a/src/xdxf.hh b/src/xdxf.hh
new file mode 100644
index 00000000..7309f1f3
--- /dev/null
+++ b/src/xdxf.hh
@@ -0,0 +1,23 @@
+/* This file is (c) 2008-2009 Konstantin Isakov <ikm@users.berlios.de>
+ * Part of GoldenDict. Licensed under GPLv3 or later, see the LICENSE file */
+
+#ifndef __XDXF_HH_INCLUDED__
+#define __XDXF_HH_INCLUDED__
+
+#include "dictionary.hh"
+
+/// Support for the XDXF (.xdxf(.dz)) files.
+namespace Xdxf {
+
+using std::vector;
+using std::string;
+
+vector< sptr< Dictionary::Class > > makeDictionaries(
+                                      vector< string > const & fileNames,
+                                      string const & indicesDir,
+                                      Dictionary::Initializing & )
+    throw( std::exception );
+
+}
+
+#endif