Make sure first that you install the Optware repositories so that you can install Lighttpd web server and the PHP interpreter
Install lightppd & php-fcgi packages
Edit the lighttpd configuration file
Locate the file lighttpd.conf and edit it in /opt/etc/lighttpd. Make sure that you first make a backup copy.
Your done. The php-cgi configuration file is picked up automatically from the conf.d sub-directory, so no further changes are necessary.
If you want the web server to start automatically at boot time do the following:
For testing point your browser to the Slug Address and port 8081:
Create a file named info.php in /opt/share/www
Point your browser to http://slugos:8081/info.php. You should get the PHP status/configuration web page.