IBM has an open-source project known as
International Components for Unicode
"The International Components for Unicode (ICU) libraries provide robust and full-featured Unicode services on a wide variety of platforms. ICU supports the most current version of the Unicode standard, and they provide support for supplementary Unicode characters (needed for GB 18030 repertoire support).
As computing environments become more heterogeneous, software portability becomes more important. ICU lets you produce the same results across all the various platforms you support, without sacrificing performance.
ICU has been released under the X License.
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