Advice to authors of Macaulay2 packages:

Macaulay2 is an aggregate, with the packages in this "packages" directory being
separate components, each with its own set of authors, copyright, and license.
Since your package will be distributed as part of Macaulay2, your software
should be licensed in a way that allows us to do that.

Macaulay2 is currently licensed under GNU General Public License (GPL) version
2, and soon also under version 3.  Either of those licenses also allow those
who receive Macaulay2 to modify it and to redistribute it, so your software
should also be licensed in a way that allows them to do that.

One possibility is for the your software to be put into the public domain.  In
that case, you may adapt a brief license statement from the following model,
and insert it as a comment in your file.

   {*
   Copyright 2010, 2011 Joe Smith.

   This file is in the public domain.
   *}

Alternatively, you may consider licensing your software under the GPL.
Information about the GPL can be obtained here:

    http://www.gnu.org/licenses/gpl.html

Instructions for how to formulate your copyright notice and how to license your
software under GPL can be obtained here:

    http://www.gnu.org/licenses/gpl-howto.html

Alternatively, you may adapt a brief license statement from the following
model.

   {*
   Copyright 2009, 2010 Joe Smith and Jane Doe.

   You may redistribute this file under the terms of the GNU General Public
   License as published by the Free Software Foundation, either version 2 of
   the License, or any later version.
   *}

As Macaulay2 is an aggregate, and the packages will not be linked with code
licensed under GPL version 3, a package licensed just under version 2 would
also be acceptable.
