Unicode normalization in PHP

Unicode normalization is available in the standard class Normalizer with PHP 5.3 or the PECL extension intl.

$nfd  = Normalizer::normalize($str, Normalizer::Form_D);
$nfc  = Normalizer::normalize($str, Normalizer::Form_C);
$nfkd = Normalizer::normalize($str, Normalizer::Form_KD);
$nfkc = Normalizer::normalize($str, Normalizer::Form_KC);