MariaDB has been making successful parallel-to-MySQL-releases since MariaDB 5.1. The feature list is bursting with new features which has helped more & more folk migrate their MySQL instances to MariaDB. This talk will focus on the main feature additions in MariaDB, from MariaDB 5.1 to the flagship MariaDB 5.5 release. This includes features like an improved query optimizer, join optimizations, group-commit, ALTER TABLE progress report etc. A brief overview of coming features for MariaDB 5.6 (and MySQL 5.6) will also be given.