skeinsum is an implementation of version 1.3 of the Skein cryptographic hash function. It is licensed under version 3 of the GNU General Public License or, at your option, any later version. See COPYING for details. See the INSTALL file for installation information. Once the software is installed, invoke skein256sum, skein512sum, or skein1024sum with the --help option to see usage information. The skeinsum home page is http://jxself.org/skein.shtml. Information about the Skein cryptographic hash function itself is available at http://www.skein-hash.info/