The m17n library provides following facilities to handle multilingual
text.

    * M-text: A data structure for a multilingual text.  It is
      basically a string but with attributes called text property, and
      is designed to substitute for the C string.  It is the most
      important object of the m17n library.

    * Functions for creating and processing M-texts.

    * Functions for converting M-texts from/to strings encoded in
      various existing formats.

    * A huge character space, which contains all the Unicode
      characters and more non-Unicode characters.

    * Chartable: A data structure that contains per-character
      information efficiently.

    * Functions for inputting and displaying M-text on a window
      system.

WWW: http://www.m17n.org/m17n-lib/