MySql

MySQL is a relational database management system (RDBMS) which has more than 6 million installations. MySQL stands for "My Structured Query Language". The program runs as a server providing multi-user access to a number of databases.

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.

MySQL is commonly used by free software projects which require a full-featured database management system, such as WordPress, phpBB and other software built on the LAMP software stack. It is also used in very high-scale World Wide Web products including Google and Facebook.

Source: Wikipedia
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