UDF requires %PHP5% and %PECL_Gen% from the %PECL% repository. UDF_Gen itself is not (yet?) part of %PECL% but available independently at %http://www.php-groupies.de/php/UDF_Gen-0.2.0.tgz% %PECL_Gen% and %UDF_Gen% are both installed using the %PECL% installer