Echolot is (c) 2002 Peter Palfrader Echolot is free software. you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it 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 The lib directory includes software by Peter J. Acklam : - Math::SpecFun::Erf - Statistics::Distrib::Normal Those modules may be distributed under the same terms as Perl itself (the GNU General Public License and the Artistic License).