In Apache2 I configured PHP as CGI in a virtual host: SetEnv PHPRC "/usr/local/php5.3" ScriptAlias /php5.3 "/usr/local/php5.3/bin" Action application/php5.3 /php5.3/php-cgi AddType application/php5.3 .php Everything works fine. Now I have some issues with the standard version of the GD because it restricts me in settings several hinting and anti-aliasing stuff for fonts. Therefore I want to modify the GD source and create a new shared library. Since I don't want a modifed library in my system I want only PHP to use that library. My question now: How can I change the Apache configuration in a way that PHP uses a certain new version of the library? Something like this does not work: ScriptAlias /php5.3 "LD_LIBRARY_PATH=/path/to/my/lib:$LD_LIBRARY_PATH /usr/local/php5.3/bin"