The Aspell Czech dictionary is based on the MySpell One:

  This dictionary is based on a subset of the
  Czech wordlist created by Tomas Cermak (original
  author) and contributors Petr Prenghy, Hanus Adler
  and Petr Kolar for ispell and his original version
  is located on ftp://ftp.vslib.cz/pub/unix/ispell/czech/.

  The affix file is a modified version of the czech.aff
  file and is licensed under the terms of the GNU GPL2
  as published by the Free Software Foundation.

  Thanks to authors for there wonderful work.

  The modifications to the affix file and wordlist to make it work
  with Myspell are (c) 2002 Libor Rejc (rejc@mail.cz) and are
  also covered by the GPL version 2 license.

  These files are distributed in the hope that they will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software Foundation,
  Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

Original MySpell README file and affix file can be found in the doc/
directory.
