In 2009, Oracle purchased Sun Microsystem who was the keeper of MySQL. When that happened, some of the original developers of MySQL were concerned about future developments and created a MySQL fork which they called MariaDB.
Fast forward to today, and MariaDB has turned into a direct competitor to MySQL, even displacing it in several environments. It is used by major companies such as Google, Facebook and Wikipedia.
Right from the start, MariaDB were committed to maintaining 100% compatibility, thus every library developed in any language for MySQL should work correctly with MariaDB. Saying that, it is inevitable that, with time passing, differences will develop and old applications using MySQL may need to be upgraded. This is not really an issue as the same would happen between a very early version of MySQL and the very latest one.
Besthost will be upgrading all its servers to use MariaDB by the end of September 2017. If your website is hosted by us and you have any concerns about this procedure, please get in touch.