SJFonts are licensed under the GNU General Public License Version 2
as included in the COPYING file but with the following expection:

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.