Plesk provides full support for the PHP scripting language, including
support for multiple PHP versions and handler types out of the box. This
topic explains how Plesk administrator can make PHP handler types
available for their customers and to configure PHP settings for
individual PHP versions.
Making handler types available to your customers
To make a particular combination of PHP version and handler type
available or unavailable to your customers, go to Tools & Settings >
PHP Settings. You will be presented with the list of all
combinations of PHP version and handler type available on the server:
The 
icon next to a PHP version + handler type
combination indicates that it is available to your customers and can be
chosen, and the 
icon indicates that the combination is
unavailable. Click the icon to toggle the availability of a particular
PHP version + handler type combination. Any customer who has the
permission to choose the PHP version and handler type for their domains
will be able to select any of the PHP version + handler type
combinations that you make available. The number of domains using a PHP
version + handler type combination is displayed to the right of its
name, and you can click the number to see the list of domains using that
combination.
Different handler types vary in how secure they are and how much
resources they consume. You can use this functionality to prohibit your
customers from using a particular handler type, or a particular PHP
version (by making all PHP version + handler type combinations using
that PHP version unavailable). For example, by default, the CGI PHP
handler is unavailable for all PHP versions. However, you can make it
available for a particular PHP version, or for all of them. If you are
not sure what PHP handlers to make available, read about the different
PHP handler types here.