Tutorial: Basic C Programming Skill for Chinese Computing
: Useful, but doesn't cover any wchar capabilities.
wchar.h: Wide Character Types and Functions
Concepts of C/UNIX Internationalization
Programming for Internationalization FAQ
libtabe
is a "library which provides useful Chinese functions/routines that can deal with fundamental elements such as pronunciation(BoPoMoFo), character frequency, word identification, word frequency. It also comes with a large free word database."
Rosette
: a C++ library for Unicode
IBM C/C++ Classes for Unicode
Mark Leisher's Unicode libraries
libutf8
- a Unicode/UTF-8 locale plugin
Character Set Conversion Library