@node License and Copyright, Concept Index, Acknowledgments, Top
@chapter License and Copyright

FFTW is Copyright @copyright{} 2003, 2007-11 Matteo Frigo, Copyright
@copyright{} 2003, 2007-11 Massachusetts Institute of Technology.

FFTW 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.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA You can also
find the @uref{http://www.gnu.org/licenses/gpl-2.0.html, GPL on the GNU
web site}.

In addition, we kindly ask you to acknowledge FFTW and its authors in
any program or publication in which you use FFTW.  (You are not
@emph{required} to do so; it is up to your common sense to decide
whether you want to comply with this request or not.)  For general
publications, we suggest referencing: Matteo Frigo and Steven
G. Johnson, ``The design and implementation of FFTW3,''
@i{Proc. IEEE} @b{93} (2), 216--231 (2005).

Non-free versions of FFTW are available under terms different from those
of the General Public License. (e.g. they do not require you to
accompany any object code using FFTW with the corresponding source
code.)  For these alternative terms you must purchase a license from MIT's
Technology Licensing Office.  Users interested in such a license should
contact us (@email{fftw@@fftw.org}) for more information.