MySQL Native Driver (Mysqlnd)
MySQL Native Driver is a replacement for the MariaDB Client Library (libmysql). MariaDB Native Driver is part of the official PHP sources as of PHP 5.3.0.
The MariaDB database extensions MariaDB extension, mysqli and PDO MYSQL all communicate with the MariaDB server. In the past, this was done by the extension using the services provided by the MariaDB Client Library. The extensions were compiled against the MariaDB Client Library in order to use its client-server protocol.
With MariaDB Native Driver there is now an alternative, as the MariaDB database extensions can be compiled to use MariaDB Native Driver instead of the MariaDB Client Library.
MySQL Native Driver is written in C as a PHP extension.