Thanks for your answer. I modified the CentOS+ RPM/spec file so that you can install PHP5 in parallel to PHP4 (shared PHP pear with PHP4). Additionally, I added a fcgi package which contains a FastCGI enabled PHP binary. No extensive testing so far but the installation of Mediawiki 1.9 went smoothly. You will probably want to disable either /etc/httpd/conf.d/php5.conf or /etc/httpd/conf.d/php.conf because using both modules in parallel is AFAIK not possible. Just in case that someone is interested: http://www.felix-schwarz.name/files/opensource/php-fcgi/5.1.6-3el4s1.5/ fs