MySQL is a relational database management system (RDBMS)  which has more than 11 million installations. The program runs as a server providing multi-user access to a number of databases.

The name "MySQL" is officially pronounced /maɪˌɛskjuːˈɛl/ (My S Q L), not "My sequel" /maɪˈsiːkwəl/. This adheres to the official ANSI pronunciation; SEQUEL was an earlier IBM database language, a predecessor to the SQL language. However, the developers do not take issue with the pronunciation "My Sequel" or other local variations.

The project's source code is available under terms of the GNU General Public License, as well as under a variety of proprietary agreements. MySQL is owned and sponsored by a single for-profit firm, the Swedish company MySQL AB, now a subsidiary of Sun Microsystems, which holds the copyright to most of the codebase. On April 20th, 2009 Oracle Corp., which develops and sells the proprietary Oracle database, announced a deal to acquire Sun Microsystems.