I am hoping craft supports MariaDB. Also, since version 10, InnoDB transaction engine in MariaDB has been replaced with XtraDB. Will this work with Craft?
Update: Craft 3 officially supports MariaDB 5.5+ now. https://docs.craftcms.com/v3/requirements.html
Not officially, no. MariaDB is supposed to a "drop-in" replacement for MySQL, but there are clearly areas where it is not 1:1 compatible with MySQL: https://mariadb.com/kb/en/mariadb/mariadb-vs-mysql-compatibility/
We've seen some installations using MariaDB where a query would actually return incorrect results and the same MySQL query on the same database returns that data correctly.