major changes:
ICU 3.0 includes the latest bug fixes, locale/charset updates, and
performance/build/porting enhancements.
- Collation
Collation data is in a separate data tree, allowing for easier
modularization and maintenance.
getFunctionalEquivalent API allows for better caching and UI support.
- Unicode 4.0.1
ICU is updated to the latest version of Unicode standard, which had
significant property changes.
- CLDR 1.1
Updates to CLDR 1.1, with many updates to locale data, and special
emphasis on collation data.
- Formatting
As an aid to migration of traditional C (stdio) and C++ (iostream)
formatting, the POSIX-like input/output library, icuio, is officially
supported.
Significant digits now supported in DecimalFormat, for general use and
%g support.
- RFC822 time zone format support in DateFormat for compatibility.
- Currency formatting/parsing improvements
Allows parsing multiple currencies with one formatter, without knowing the
currency in advance. Much cleaner design allowing extensibility to other
measurement units in the future.
- Regular expressions (C)
The regular expressions framework now features a C API, instead of just C++.
- Locales
Locale canonicalization spec defined and implemented. Provides
interoperability with POSIX and .NET locale IDs, more RFC 3066 support.
- Layout engine
Layout engine now supports using different canonically-equivalent Unicode
forms of the same text: e.g. a + ´ or á. This is especially important for
non-Latin scripts.
- Build Environment
ICU can now build its data library much faster on most platforms.
For a complete list see:
http://oss.software.ibm.com/cvs/icu/~checkout~/icu/readme.html?tag=release-3-0