There's an experimental PHP extension module which wraps the ICU library's
normalization functions. This is *MUCH* faster than doing this work in pure
-PHP code. This is at https://gerrit.wikimedia.org/r/gitweb?p=mediawiki/extensions/normal.git;a=summary.
+PHP code. This is at https://git.wikimedia.org/summary/mediawiki%2Fextensions%2Fnormal.git.
It is used by the WMF, which currently runs PHP 5.3.10 on Linux. It hasn't been
thoroughly tested on other configurations, but may work.