1. Install ICU from source
wget http://download.icu-project.org/files/icu4c/56.1/icu4c-56_1-src.tgz tar -xzvf icu4c-56_1-src.tgz cd icu/source ./configure --prefix=/usr/local/icu make && make install
2. Install intl for php
wget http://pecl.php.net/get/intl-3.0.0.tgz tar -xzvf intl-3.0.0.tgz cd intl-3.0.0 phpize ./configure –enable-intl –with-icu-dir=/usr/local/icu make && make install
then add the following line into php.ini
extension=intl.so
Centos install ICU, INTL for php
原文：http://www.cnblogs.com/mztest/p/5156897.html