GAP is

Copyright (C) (1987--2024) by the GAP Group,

incorporating the Copyright (C) 1999, 2000  by
      School of Mathematical and Computational Sciences,
      University of St Andrews,
      North Haugh, St Andrews, Fife KY16 9SS, Scotland

being the Copyright (C) 1992 by
      Lehrstuhl D fuer Mathematik, RWTH,
      52056 Aachen, Germany,
transferred to St~Andrews on July 21st, 1997.

except for files in the distribution, which have an explicit different copyright statement. In particular, the copyright of packages distributed with GAP is usually with the package authors or their institutions.

License

GAP 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.

The MS Windows binary for GAP uses cygwin and therefore is licensed under GPL version3 or (at your option) any later version. For details, see the file LICENSE in the GAP distribution or see The FSF’s own site.