If you want to use custom PHP modules, you can manage them through a PHP initialization file (more info).
To enable a PHP module, add the following line:
You'll need to add a version of this line for each module you want to enable. For a list of some PHP modules, view the list at the PHP website.
Customers using cPanel shared hosting accounts (more info), have a few additional steps they need to take.
If you want to use custom PHP modules, you must change your PHP version away from native (5.4) to 5.4 (more info).
On the page where you view your PHP version, you can also select the PHP modules you want to enable. If you do this, you do not need to modify your account's PHP initialization file.