libmysqld
The MySQL source code is covered by the GNU GPL license
(see section H GNU General Public License). One result of this is that any program
which includes, by linking with libmysqld, the MySQL
source code must be released as free software (under a license
compatible with the GPL).
We encourage everyone to promote free software by releasing
code under the GPL or a compatible license. For those who
are not able to do this, another option is to purchase a
commercial license for the MySQL code from MySQL AB.
For details, please see section 1.4.3 MySQL Licenses.