README.mysql-license
MySQL is distributed under GPL v2, but there are some licensing exceptions that allow the client libraries to be linked with a non-GPL application, so long as the application is under a license approved by Oracle. For details see http://www.mysql.com/about/legal/licensing/foss-exception/ Some innobase code from Percona and Google is under BSD license. Some code related to test-suite is under LGPLv2.