MySQL is a multithreaded, multi-user, SQL (Structured Query Language) Database
Management System (DBMS) with an estimated six million installations. MySQL AB makes MySQL available
as open source software / free software under the GNU General Public License (GPL), but they also
sell it under traditional commercial licensing arrangements for cases where the intended use is
incompatible with use of the GPL.
Unlike projects such as Apache, where the software is developed by a public community, and is
essentially not owned by anyone, MySQL is owned and sponsored by a single for-profit firm, the
Swedish company MySQL AB. The company develops and maintains the system, selling support and service
contracts, as well as commercially-licensed copies of MySQL, and employing people all over the world
who work together via the Internet. Two Swedes and a Finn founded MySQL AB: David Axmark, Allan
Larsson, and Michael "Monty" Widenius.