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. 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 officially (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. The company does not take issue with the pronunciation "My sequel" or other local variations.
MySQL works on many different system platforms, including AIX, BSDi, FreeBSD, HP-UX, i5/OS, Linux, Mac OS X, NetBSD, Novell NetWare, OpenBSD, eComStation , OS/2 Warp, QNX, IRIX, Solaris, Symbian, SunOS, SCO OpenServer, SCO UnixWare, Sanos, Tru64, Windows 95, Windows 98, Windows ME, Windows NT, Windows 2000, Windows XP, and Windows Vista. A port of MySQL to OpenVMS is also available.
Libraries for accessing MySQL databases are available in all major programming languages with language-specific APIs. In addition, an ODBC interface called MyODBC allows additional programming languages that support the ODBC interface to communicate with a MySQL database, such as ASP or ColdFusion. The MySQL server and official libraries are mostly implemented in ANSI C/ANSI C++.
To administer MySQL databases one can use the included command-line tool (commands:
mysqladmin). Also downloadable from the MySQL site are GUI administration tools: MySQL Administrator and MySQL Query Browser. Both of the GUI tools are now included in one package called tools/5.0.html MySQL GUI Tools.
In addition to the above-mentioned tools developed by MySQL AB, there are several other commercial and non-commercial tools available. Examples include phpMyAdmin, a free Web-based administration interface implemented in PHP, Navicat Lite Edition, a free desktop based GUI tool.
The MySQL Enterprise Server is released once per month and the sources can be obtained either from MySQL's customer-only Enterprise site or from MySQL's Bazaar repository, both under the GPL license. The MySQL Community Server is published on an unspecified schedule under the GPL and contains all bug fixes that were shipped with the last MySQL Enterprise Server release. Binaries are no longer provided by MySQL for every release of the Community Server.
Beginning with MySQL 5.1, MySQL AB has stopped providing these different package variants. There will only be one MySQL server package, which includes a mysqld binary with all functionality and storage engines enabled. Instead of providing a separate debug package, a server binary with extended debugging information is also included in the standard package.
Support for parallelization is also part of the roadmap for future versions.
The current MySQL 5.1 development release is 5.1.28-rc.
A new storage engine is also in the works, called Falcon. A preview of Falcon is already available on MySQL's website.
Buyers of MySQL Enterprise enjoy access to binaries and software that is certified for their particular operating system, and access to monthly binary updates with the latest bug fixes. Several levels of Enterprise membership are available, with varying response times and features ranging from how to and emergency support through server performance tuning and system architecture advice. The MySQL Network Monitoring and Advisory Service monitoring tool for database servers is available only to MySQL Enterprise customers.
MySQL Server is available as free software under the GNU General Public License (GPL), and the MySQL Enterprise subscriptions include a GPL version of the server, with a traditional proprietary version available on request at no additional cost for cases where the intended use is incompatible with the GPL.
Both the MySQL server software itself and the client libraries are distributed under a dual-licensing format. Users may choose the GPL, which MySQL has extended with a FLOSS License Exception. It allows Software licensed under other OSI-compliant Open Source licenses, which are not compatible to the GPL, to link against the MySQL client libraries.
Customers that do not wish to be bound to the terms of the GPL may choose to purchase a proprietary license.
Some users have independently continued to develop earlier versions of the client libraries, which was distributed under the less-restrictive GNU Lesser General Public License (LGPL).
In September 2005, MySQL AB and SCO forged a partnership for "joint certification, marketing, sales, training and business development work for a commercial version of the database for SCO's new OpenServer 6 version of Unix". SCO raised controversy beginning in 2003 with a number of high-profile lawsuits related to the Linux Operating System. Various MySQL employees expressed that the company was committed to serving its end users, regardless of their operating system choice, that the company would leave it to the courts to resolve the SCO licensing controversy, and that other common open source databases have also been ported to, and support, SCO OpenServer.
In October 2005, Oracle Corporation acquired Innobase OY, the Finnish company that developed the InnoDB storage engine that allows MySQL to provide such functionality as transactions and foreign keys. A press release by Oracle that was issued after the acquisition, mentioned that the contracts that make the company's software available to MySQL AB would be due for renewal (and presumably renegotiation) some time in 2006. During the MySQL Users Conference in April 2006, MySQL issued a press release which confirmed that MySQL and Innobase OY agreed to a multi-year extension of their licensing agreement.
When the beta version of MySQL 5.0 was released in March 2005, David Axmark, a co-founder of MySQL, said that "People have been criticizing MySQL since we started for not having stored procedures, triggers and views," and "We're fixing 10 years of criticism in one release. MySQL 5.0's 13 October build 5.0.15 was released for production use on 24 October 2005, after more than two million downloads in the 5.0 beta cycle.
Critical bugs sometimes do not get fixed for long periods of time. An example is a bug with status critical existing since 2003.
MySQL shows poor performance when used for Data Warehousing; this is partly due to inability to utilize multiple CPU cores for processing a single query.