Server side programming is in PHP, so PHP5 cli (command line interface) module must be installed - see also the linux installation section.
PHP setting are stored in 'php.ini' the default that comes with your distribution should be enough (assuming its recent and up to date).
If installing PHP from the sources use the 'php.ini-recommended' file included in the distribution, or the contrib/etc_php5_cli/php.ini of FreeNAC
Recommended variables set in your /etc/php5/cli/php.ini file are as follows,
Memory
memory_limit = 256M ; Maximum amount of memory a script may consume (128MB)
Error_reporting on productive servers: show all errors, except for notice. Log errors to syslog:
error_reporting = E_ALL & ~E_NOTICE log_errors = on display_errors = off error_log = syslog
On test / development servers where you wish to see all software warnings:
error_reporting = E_ALL | E_STRICT display_errors = on error_log = syslog