Our software is 100% GPL (General Public License); if yours is 100% GPL compliant, then you have no obligation to pay us for the licenses. This is a great opportunity for the open source community and those of you who are developing open source software.

The formal terms of the GPL license can be found in the GNU General Public License section of the MySQL Reference Manual. Please note that the General Public License can be restrictive, so if it doesn't meet your needs, you are better served by our Commercial License.

Specifically:

MySQL is free use for those who are 100% GPL. If your application is licensed under GPL or compatible OSI license approved by MySQL AB, you are free to ship any GPL software of MySQL AB with your application ('application' means any type of software application, system, tool or utility). You do not need a separate signed agreement with MySQL AB, because the GPL license is sufficient. We do, however, recommend you contact us as there usually are good opportunities for partnership and co-marketing.

Under the Open Source License, you must release the complete source code for the application that is built on MySQL. You do not need to release the source code for components that are generally installed on the operating system on which your application runs, such as system header files or libraries.

Free use for those who never copy, modify or distribute. As long as you never distribute the MySQL Software in any way, you are free to use it for powering your application, irrespective of whether your application is under GPL license or not.

You are allowed to modify MySQL Software source code any way you like as long as the distributed derivative work is licensed under the GPL as well.

You are allowed to copy MySQL binaries and source code, but when you do so, the copies will fall under the GPL license.

Optional GPL License Exception for PHP. As a special exception, MySQL AB gives permission to distribute derivative works that are formed with GPL-licensed MySQL software and with software licensed under version 3.0 of the PHP license. You must obey the GNU General Public License in all respects for all of the code used other than code licensed under version 3.0 of the PHP license.

FLOSS License Exception. We have created a license exception which enables Free/Libre and Open Source software ("FLOSS") to be able to include the GPL-licensed MySQL client libraries despite the fact that not all open source licenses are compatible with the GPL (this includes the PHP license version 3.0). Read more about the FLOSS License Exception.

Non-Profits, Academic Institutions, and Private Individuals
If you represent a non-profit organization or an academic institution, we recommend you publish your application as an open source / free software project using the GPL license. Thereby, you are free to use MySQL software free of charge under the GPL license. We believe that if you have strong reasons to not publish your application in accordance with the GPL, you should purchase commercial licenses.

If you are a private individual you are free to use MySQL software for your personal applications as long as you do not distribute them. If you distribute them, you must make a decision between the Commercial License and the GPL.

Please note that even if you ship a free demo version of your own application, the above rules apply.

Recommendations
Please note that MySQL AB can only give advice on which license is right for you. The final judgment, of course can be made only by a court of law. With that said, we recommend the commercial license to all commercial and government organizations. This frees you from the broad and strict requirements of the GPL license.

To all free software enthusiasts we recommend our products under the GPL license. We believe that MySQL AB is one of the world's largest companies that offers all its software under the GPL license.

To anyone in doubt, we recommend the commercial license. It is never wrong. Thanks to our cost-effective way of producing software, we are able to sell our commercial licenses at prices well under the industry average.

Older Versions
Note that some older versions of the MySQL database server (prior to 3.23.19) are using the Version 4, March 5, 1995, license. See the documentation for the specific version for more information.

When in Doubt
If you have any questions about Licensing, please contact the MySQL Sales Team to explore the options available for your specific scenario. http://www.mysql.com/buy-mysql

OSI = Open Source Initiative, www.opensource.org/licenses
GPL = GNU General Public License, http://www.gnu.org/copyleft/gpl.html

Version 4.1, 12 March 2004