In October of 2015, we added support for the popular open source MariaDB database in Amazon RDS and have since seen rapid adoption by customers. Amazon RDS supports MariaDB instances running in Single-AZ or Multi-AZ configurations in all AWS regions. Today we are extending the RDS Service Level Agreement ("SLA") that covers Multi-AZ instances for MySQL, Oracle, and PostgreSQL to include Amazon RDS for MariaDB. 

Source: Amazon Web Services News