diff --git a/doc/src/Intro_opensource.rst b/doc/src/Intro_opensource.rst index 635982fd18..fa857e5014 100644 --- a/doc/src/Intro_opensource.rst +++ b/doc/src/Intro_opensource.rst @@ -1,40 +1,61 @@ 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 +GPL version of LAMMPS +^^^^^^^^^^^^^^^^^^^^^ + +LAMMPS is an open-source code, available free-of-charge, and distributed +under the terms of the `GNU Public License Version 2 `_ (GPLv2), +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 - +specifically in binary form - or are distributing 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. +LAMMPS comes with no warranty of any kind. + +As each source file states in its header, it is a copyrighted code, and +thus not in the public domain. For more information about open-source +software and open-source distribution, see `www.gnu.org `_ +or `www.opensource.org `_. The legal text of the GPL as it +applies to LAMMPS is in the LICENSE file included in the LAMMPS distribution. .. _gpl: https://github.com/lammps/lammps/blob/master/LICENSE +.. _lgpl: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html + .. _gnuorg: http://www.gnu.org .. _opensource: http://www.opensource.org -Here is a summary of what the GPL means for LAMMPS users: +Here is a more specific summary of what the GPL means for LAMMPS users: -(1) Anyone is free to use, modify, or extend LAMMPS in any way they +(1) Anyone is free to use, copy, 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. +open-source, meaning you are required to distribute **all** of it under +the terms of the GPL. You should clearly annotate such a modified 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. +the terms of the GPL. You may write code that interfaces LAMMPS to +a differently licensed library. In that case the code that provides +the interface must be licensed GPL, but not necessarily that library +unless you are distributing binaries that require the library to run. (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. + + +LGPL version of LAMMPS +^^^^^^^^^^^^^^^^^^^^^^ + +We occasionally make stable LAMMPS releases available under the `GNU +Lesser Public License v2.1 `_. This is on request only and with +non-LGPL compliant files removed. This allows uses linking non-GPL +compatible software with the (otherwise unmodified) LAMMPS library +or loading it dynamically at runtime. Any **modifications** to +the LAMMPS code however, even with the LGPL licensed version, must still +be made available under the same open source terms as LAMMPS itself.