ICU Legal Issues


ICU and Your Product's License List


Include in your list of licenses the current versions of both of the following licenses (follow the links to get the current versions), regardless of whether your product ships with ICU only in binary form - shared libraries (.dll, .so, .sl, etc.) and/or compiled data (.dat, .cnv, .res, etc.) - and/or with ICU source files and/or ICU documentation.

For the code entitled [ICU4C and/or ICU4J and/or ICU4JNI]:

Providing ICU source files

If you ship ICU source code (.c, .cpp, .java, .h, etc.), plain-text source data files (.txt, .ucm, ...), and/or ICU documentation (.html, .pdf, ...), whether modified or not, then you also need to leave the copyright notices in each source file.

(Historical note: For binary-only shipments, the inclusion of the ICU license is necessary with the X license style used since ICU4C 1.8.1/ICU4J 1.3.1. It was not required with ICU4C 1.8.0/ICU4J 1.3.0 and earlier which used the IBM Public License. ICU4C and ICU4J changed at the same time: At that time, ICU4C and ICU4J version numbers were not yet synchronized.)

X License and Copyrights

The ICU projects use the X license, with the exact text at ICU4C License and ICU4J License. The X license [which used to be available at but seems to be moving around] is a simple open-source license that is still compatible with GPL without forcing ICU to be GPL or your project to be open-source. All code contributed to the projects must be covered by this license, which includes an IP license allowing anyone to use the code without charge.

The ICU project contains code with non-IBM copyrights.

Other Open-source Projects

You can use ICU code in other Open Source projects. While ICU is not under the GNU license, the X license that ICU uses is listed under GPL-Compatible, Free Software Licenses (under the X11 heading).

Old Versions of ICU

ICU (ICU4C) before release 1.8.1 and ICU4J before release 1.3.1 (before June of 2001) are covered by the IBM Public License, an open-source license developed by IBM attorneys and approved by leaders of the open-source community. All code contributed to the projects was covered by this license.