** GPL v2 license with font embedding exception:

http://www.gnu.org/licenses/old-licenses/gpl-2.0-faq.html#FontException

As a special exception, if you create a document which uses this
font, and embed this font or unaltered portions of this font into 
the document, this font does not by itself cause the resulting 
document to be covered by the GNU General Public License. This 
exception does not however invalidate any other reasons why the 
document might be covered by the GNU General Public License. If you 
modify this font, you may extend this exception to your version of 
the font, but you are not obligated to do so. If you do not wish to 
do so, delete this exception statement from your version.
