MontyProgram AB, the company formed by MySQL creator Michael "Monty" Widenius in the wake of his break with Sun Microsystems, has released the latest version of MariaDB, a “drop-in replacement” for MySQL built on the MySQL 5.5 codebase. MariaDB 5.5.23, which according to developer Colin Charles has "1.5 million additional lines of code compared to MySQL," pushes forward the development of an open-source database with features that aim to match those of Oracle’s commercial-only MySQL releases.

Widenius, who lives in Helsinki, left Sun in 2009 when he became dissatisfied with the approach the company was taking to MySQL. Since then—and particularly after Sun’s acquisition by Oracle—much of the MySQL development team has left to join Widenius’ company, or to work on one of the other "forks" of the MySQL code line, including Brian Aker’s Drizzle and Peter Zaitsev’s Percona. SkySQL, a company made up largely of former MySQL AB employees, was launched to offer support for MariaDB, MySQL, and Drizzle for those dissatisfied with Oracle’s new licensing model. Oracle has continued development of MySQL, but stirred discontent in the MySQL community when the company shifted the development model away from a fully open-source approach to an "open core," with new enterprise features offered under a commercial license only.

Some of the new features in MariaDB mirror those added in Oracle’s commercial releases of MySQL Enterprise. For example, MariaDB 5.5 includes a plug-in to allow client authentication through Pluggable Authentication Modules (allowing users or applications to use Lightweight Directory Access Protocol (LDAP) or other authentication systems as credentials for access instead of a password stored within the database) and a high-performance thread pool to help maintain server performance with large numbers of connected clients.

Some of the other high performance features were "developed for a very large social networking site," according to the company, including a non-blocking client library that allows applications to run multiple parallel connections to one or more databases—for tasks like data merges across "shard" databases in very large database implementations. There are also other features aimed at developers of geospatial applications based on the Open Geospatial Consortium’s OpenGIS standards.

The stable release of MariaDB can be downloaded from Mariadb.org.

Update: Earlier versions of MariaDB have also gotten update, as Widenius reported in his blog, because "we found a very serious security issue in all recent MariaDB / MySQL releases and we strongly recommend everyone to upgrade to one of the above releases ASAP." The vulnerability was also reported to Oracle, and Widenius expects that Oracle will also soon issue a MySQL update.