A GAP Package to Calculate Group Cohomology and Massey Products

Version 1.5
Released 2018-10-11

This project is maintained by The GAP Team

Build Status Code Coverage


This GAP package computes cohomology rings for finite p-groups using Jon Carlson’s method, both as GAP objects, and also in terms of generators and relators. It also computes induced homomorphisms on cohomology and Massey products in the cohomology ring.

The latest version of this package is normally bundled with GAP, so it should not be necessary to manually install it. However, if needed, you can always download the latest version from

Please refer to the package documentation for more information.


Please submit bug reports, suggestions for improvements and patches via the issue tracker.


CRIME 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. For details, see the file COPYING` distributed as part of this package or see the FSF’s own site.