"Launched by MySQL creator Michael "Monty" Widenius, the MariaDB
MySQL fork has been released for downloading as version 5.2. The
open source database is based on MySQL 5.1.51, although MariaDB
contains additional functions. The release notes say that all
commands, interfaces, libraries, and APIs from MySQL also run in
MariaDB so it's a drop in replacement for current installations. No
innovations were added following the Release Candidate; instead,
the developers concentrated on troubleshooting."