Download ICU 52


ICU is the premier library for software internationalization. ICU 52.1 is a major release of ICU, with new features, new APIs and many bug fixes in data and code.

Major changes since ICU 51 include the following:

Common Changes

    • Unicode 6.3: New bidi control codes, new Bidi_Class property values, two new bidi "bracket" properties; for other property value changes see the UAX #44 summary (tickets #10128, #10168).

      • The bidi algorithm implementation has also been updated to support the new properties and to match the updated algorithm in the Unicode 6.3 version of UAX #9 (ticket #10142).

      • Note: ICU 52 still uses collation root data based on Unicode Collation Algorithm 6.2 (UCA 6.2). (However, ICU 52 does use CLDR 24 collation tailoring data.)

    • CLDR 24: Improved coverage for top 70+ languages, fractional plural rules and forms, many new measurement units, major simplification of collation rule syntax, preliminary version of European Ordering Rules, new relative fields such as “last Sunday” and “now”, and much more (tickets #10222, #10335, #10380, #10404)

    • Time zone data: 2013g (ticket #10037).

    • Support new variants of Islamic calendar:

      • "islamic-umalqura": Umm al-Qura (ticket #8449).

      • "islamic-tbla": Tabular (fixed intercalary years), with astronomical epoch (ticket #10249).

    • Made Calendar getDayOfWeekType behave as documented (ticket #10061).

    • New API for converting between Windows time zone ID and IANA tz database ID (ticket:#10148)

    • Technology Preview: New API for more granular control of DateFormat parse leniency (ticket #10261).

    • DateTimePatternGenerator:

      • Support recently-added time zone pattern characters O, X, x and updated support for V, Z (ticket #10065)

      • Support newly-defined skeleton character ‘J’ to generate preferred hour cycle without any day period indicator (such as AM/PM for h) (ticket #10378).

    • Implement support for plurals that depend on displayed fractional values (tickets #8474, #10253, #10273).

      • MessageFormat and currency formatting etc. select appropriate plural forms for values with decimal digits (after the decimal point).

    • Segmentation:

      • Add dictionary-based word & line break for Lao (ticket #7647).

      • Prevent line break between SY and HL for Hebrew usage such as “‎קח/י”, “‎כתב/ה”, and “‎שחקנים/יות” (ticket #10176).

      • Fix word break to correctly handle katakana words with vowel extender ‘ー’ \u30FC (ticket #10299).

  • Many other bug & API doc fixes.

ICU4C Specific Changes

  • Improved implementation of thread synchronization, using safer and more efficient APIs on most platforms. It was necessary to deprecate and disable the runtime-customization of mutex functions. Build-time customization is still possible. (ticket #10051)

  • Added plain C wrappers for Region class (ticket #10070).

  • Added plain C wrappers for NumberingSystem class (ticket #10039).

  • Added plain C wrapper for Formattable, and functions for parsing & formatting of number objects including BigDecimal equivalent (ticket #7912).

ICU4J Specific Changes

  • (none)

Known Issues

    • C: In some environments (newer clang, older gcc/libstdc++) ICU may fail to build, see #10272 for workaround.

    • C: C++ comments were incorrectly used in C source code. --disable-strict as a configure option may work around this issue. Issue #10710

Updates in ICU 52.2

  • New Japanese era Reiwa (令和) support

  • IANA tzdata2019a

ICU4C Download

Latest ICU4C 52 Release

Version: 52.2

Release Date: 2019-04-11

Source and binary downloads are available on the git/GitHub tag page:

Previous ICU4C 52 Releases

Version: 52.1

Release Date: 2013-10-09

ICU4C Supported Platforms

Key to testing frequency

Frequently tested

ICU will work on these platforms with these compilers

Rarely tested

ICU has been ported to these platforms but may not have been tested there recently

ICU4J Download

Latest ICU4J 52 Release

Version: 52.2

Release Date: 2019-04-11

Source and binary downloads are available on the git/GitHub tag page:

Maven dependency:






Previous ICU4J 52 Releases

Version: 52.1

Release Date: 2013-10-09