MariaDB

MariaDB is a community-created fork of the popular database management system, MySQL. This fork was driven by the fact that Oracle acquired Sun, which owned MySQL AB, which was sold from Michael "Monty" Widenius, for 1 billion USD. This replacement database aims to keep high compatibility with MySQL, so that you can replace it easily, plus, it adds in XtraDB, a replacement to InnoDB(MySQL's storage engine). It is named after one of Monty's daughers, Maria.

Development

 * MariaDB's API is highly similar to MySQL, which allows you to drop in Maria over MySQL, and it is almost guaranteed to work
 * Maria versioning numbers, up to v5.5, are matched up to MySQL's releases too. Although this changed after v5.5, after 5.5, developers bumped the version up to 10, and did not guarantee MySQL imported feature anymore for similar versioning numbers.