The International Components for Unicode (ICU) is a C library that provides a full-featured, industrial strength, Unicode support.
The library provides:
ICU is a collaborative, open-source development project jointly managed by a group of companies and individual volunteers throughout the world, using the Internet and the Web to communicate, plan, and develop the software and documentation.
The ICU project is licensed under the IBM® Public License, which has been approved by the Open Source Initiative.