Is RDS for MySQL Compatible with MariaDB?
MariaDB is a branch of the MySQL source code. It is maintained by the open-source community and uses GPL licensing. One of the reasons for developing MariaDB is that Oracle acquired MySQL, so there is a chance that MySQL could get shut down. The community developed MariaDB to protect against this risk.
MariaDB is compatible with MySQL. There is no difference for front-end applications such as PHP, Perl, Python, Java, .NET, MyODBC, Ruby, and MySQL C connector.