###################
Server Requirements
###################

`PHP <http://php.net/>`_ version 7.2 or newer is required, with the 
`*intl* extension <http://php.net/manual/en/intl.requirements.php>`_ 
installed. 

The following PHP extensions should be enabled on your server:
``php-json``, ``php-mbstring``, ``php-mysqlnd``, `php-xml``

In order to use the :doc:`CURLRequest </libraries/curlrequest>`, you will need 
`libcurl <http://php.net/manual/en/curl.requirements.php>`_ installed.

A database is required for most web application programming.
Currently supported databases are:

  - MySQL (5.1+) via the *MySQLi* driver
  - PostgreSQL via the *Postgre* driver
  - SQLite3 via the *SQLite3* driver

Not all of the drivers have been converted/rewritten for CodeIgniter4.
The list below shows the outstanding ones.

  - MySQL (5.1+) via the *pdo* driver
  - Oracle via the *oci8* and *pdo* drivers
  - PostgreSQL via the *pdo* driver
  - MS SQL via the *mssql*, *sqlsrv* (version 2005 and above only) and *pdo* drivers
  - SQLite via the *sqlite* (version 2) and *pdo* drivers
  - CUBRID via the *cubrid* and *pdo* drivers
  - Interbase/Firebird via the *ibase* and *pdo* drivers
  - ODBC via the *odbc* and *pdo* drivers (you should know that ODBC is actually an abstraction layer)

