diff --git a/diff_ext_for_kdiff3/diffextstring.h b/diff_ext_for_kdiff3/diffextstring.h
deleted file mode 100644
index 05788f7..0000000
--- a/diff_ext_for_kdiff3/diffextstring.h
+++ /dev/null
@@ -1,176 +0,0 @@
-/*
- * Copyright (c) 2003, Sergey Zorin. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
-
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. 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.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
- *
- */
-
-
-#ifndef string_h
-#define string_h
-
-#include <windows.h>
-#include <tchar.h>
-
-#include <string.h>
-#include <stdlib.h>
-
-class STRING;
-inline STRING operator+( const STRING& s1, const STRING& s2);
-
-class STRING {
-  public:
-    static const int begin = 0;
-    static const int end = -1;
-
-  public:
-    STRING(const STRING& s) {
-      _str = new TCHAR[s.length()+1];
-      lstrcpy(_str, s);
-    }
-
-    STRING(const TCHAR* str = TEXT("")) {
-      _str = new TCHAR[lstrlen(str)+1];
-      lstrcpy(_str, str);
-    }
-
-    ~STRING() {
-      delete[] _str;
-    }
-
-    void resize( size_t newLength )
-    {
-       size_t oldLength = length();
-       if ( newLength < oldLength ) {
-          _str[newLength] = 0; // Just truncate the string
-       } else if( newLength>oldLength) {
-          TCHAR* p = new TCHAR[ newLength + 1 ];
-          lstrcpy(p, _str);
-          for( size_t i=oldLength; i<newLength; ++i)
-             p[i]=TEXT(' ');
-          p[newLength]=0;
-       }
-    }
-
-    STRING& operator=(const STRING& s) {
-      delete[] _str;
-      _str = new TCHAR[s.length()+1];
-      lstrcpy(_str, s);
-      return *this;
-    }
-
-    operator TCHAR*() {
-      return _str;
-    }
-
-    operator const TCHAR*() const {
-      return _str;
-    }
-
-    const TCHAR* c_str() const {
-       return _str;
-    }
-
-    size_t length() const {
-      return _tcslen(_str);
-    }
-
-    // Also returns the length. Behaviour like std::basic_string::size.
-    // See also sizeInBytes() below.
-    size_t size() const {
-      return length();
-    }
-
-    // String length in bytes. May differ from length() for Unicode or MBCS
-    size_t sizeInBytes() const {
-      return length()*sizeof(TCHAR);
-    }
-
-    bool empty() const
-    {
-       return length()==0;
-    }
-
-    STRING substr(size_t from, size_t len=size_t(-1)) const {
-      STRING tmp;
-      size_t to = len==size_t(-1) ? length() : from + len;
-
-      if(from < to && (to <= length())) {
-        size_t new_len = to - from + 1;
-        TCHAR* new_str = new TCHAR[new_len+1];
-        lstrcpyn(new_str, &_str[from], int(new_len) );
-        new_str[new_len] = 0;
-
-        tmp = new_str;
-        delete[] new_str;
-      }
-
-      return tmp;
-    }
-
-    STRING& replace( size_t pos, size_t num, const STRING& s )
-    {
-       *this = substr( 0, pos ) + s + substr( pos+num );
-       return *this;
-    }
-
-    bool operator ==(const STRING& s) const {
-      return (lstrcmp(_str, s) == 0);
-    }
-
-    size_t find(const STRING& s) const
-    {
-       const TCHAR* p = _tcsstr( _str, s._str );
-       if (p)
-          return p - _str;
-       else
-          return size_t(-1);
-    }
-
-    STRING& operator +=(const STRING& s) {
-      TCHAR* str = new TCHAR[lstrlen(_str)+s.length()+1];
-
-      lstrcpy(str, _str);
-      lstrcat(str, s);
-
-      delete[] _str;
-
-      _str = str;
-
-      return *this;
-    }
-
-  private:
-    TCHAR* _str;
-};
-
-inline STRING operator+( const STRING& s1, const STRING& s2) {
-  STRING tmp(s1);
-
-  tmp+=s2;
-
-  return tmp;
-}
-
-
-
-#endif // __string_h__