What license is Ensignia released under?

The Ensignia program itself, which is a derivate of SquirrelMail, is released under the same license as SquirrelMail: GNU General Public License version 2. However, the Ensignia skins and the skinning engine, are released under a proprietary commercial license. In order to use the skins, you must first purchase the commercial license from Ensignia.