PHP is an open source scripting language. It's usually intended to run as a module for Apache but can also be used with Microsoft IIS using the PHP Isapi filter.

Its configuration file is /etc/php.ini on Linux () and c:/windows/php.ini on Windows (may vary and may be located in the PHP installation directory).

Nectil doesn't package PHP, it should be installed separately.

On Debian or Ubuntu the PHP configuration file is in /etc/php5/apache2/php.ini.
On these distributions you should also install the package php5-cli to have the command line version of PHP (and not only the Apache Module). Be sure to enable the mysql extension (extension=mysql.so) on the php-cli version.

Configuration advices

Configure the memory_limit to at least 128M.

Configure the post_max_size and the upload_max_filesize to 100M, to allow large file uploads in Nectil.

If your website receives many visitors, think of changing the session.save_path.
PHP is by default configured to place the session datas in the /tmp directory (which is on the boot disk, usually a small partition). If you have many visitors these datas could rapidly grow and make your boot disk full. We usually use /home/php_sessions/.