1.5. LAMMPS open-source license¶
LAMMPS is a freely-available open-source code, distributed under the terms of the GNU Public License Version 2, which means you can use or modify the code however you wish for your own purposes, but have to adhere to certain rules when redistributing it or software derived from it or that includes parts of it.
LAMMPS comes with no warranty of any kind. As each source file states in its header, it is a copyrighted code that is distributed free-of- charge, under the terms of the GNU Public License Version 2 (GPLv2). This is often referred to as open-source distribution - see www.gnu.org or www.opensource.org. The legal text of the GPL is in the LICENSE file included in the LAMMPS distribution.
Here is a summary of what the GPL means for LAMMPS users:
(1) Anyone is free to use, modify, or extend LAMMPS in any way they choose, including for commercial purposes.
(2) If you distribute a modified version of LAMMPS, it must remain open-source, meaning you distribute all of it under the terms of the GPL. You should clearly annotate such a code as a derivative version of LAMMPS.
(3) If you release any code that includes or uses LAMMPS source code, then it must also be open-sourced, meaning you distribute it under the terms of the GPL.
(4) If you give LAMMPS files to someone else, the GPL LICENSE file and source file headers (including the copyright and GPL notices) should remain part of the code.