Instead of using the Mozilla Public License, you may instead elect to use the GNU General Public License (GPL) for a particular copy of expat. The election to use the GPL is irrevocable for that particular copy. If you do elect to use the GPL, then you must replace the copyright notice on each file with the following:
expat XML parser Copyright (C) 1998 James Clark This program 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.
and you must change readme.html to say that an election has been made to use this copy under the GPL. If you redistribute expat, you should also include a copy of the GPL.
Note that I will probably not accept patches under terms that allow me to distribute them only under the GPL.
James Clark