The conventional and GNU-recommended way to apply GPL-family licenses is via a copyright and license notice in the source files (GNU’s preference, in case individual files are copied out of the software), or at least in a README or COPYING file somewhere. Here are the GNU project’s recommendations on the subject.
The license and copyright statement conventionally specifies which GPL license versions may be applied, and many but not all projects use the “either version 3 of the License, or (at your option) any later version” language to allow subsequent GPL versions. When the project only says “GPLv3,” as in this case, the conservative assumption is that no later versions are permitted. However, experience shows that this doesn’t always match upstream authors’ intent.
Since there is no GPL version later than 3.0 now or in the immediate future, the distinction between GPLv2 and GPLv2+ is currently much more important than the distinction between GPLv3 and GPLv3+ when it comes to license compatibility. However, as a Linux distribution packager (my case), or as a library user working in an environment with strict requirements on documenting dependencies (which seems increasingly common), it’s important to be able to precisely document license terms—thus the request for clarification, or for the addition of a standard GNU-style copyright and license notice somewhere in the project.
Could you please clarify whether the license of this project is intended to be (in SPDX terms) GPL-3.0-only or GPL-3.0-or-later?
The conventional and GNU-recommended way to apply GPL-family licenses is via a copyright and license notice in the source files (GNU’s preference, in case individual files are copied out of the software), or at least in a README or COPYING file somewhere. Here are the GNU project’s recommendations on the subject.
The license and copyright statement conventionally specifies which GPL license versions may be applied, and many but not all projects use the “either version 3 of the License, or (at your option) any later version” language to allow subsequent GPL versions. When the project only says “GPLv3,” as in this case, the conservative assumption is that no later versions are permitted. However, experience shows that this doesn’t always match upstream authors’ intent.
Since there is no GPL version later than 3.0 now or in the immediate future, the distinction between GPLv2 and GPLv2+ is currently much more important than the distinction between GPLv3 and GPLv3+ when it comes to license compatibility. However, as a Linux distribution packager (my case), or as a library user working in an environment with strict requirements on documenting dependencies (which seems increasingly common), it’s important to be able to precisely document license terms—thus the request for clarification, or for the addition of a standard GNU-style copyright and license notice somewhere in the project.
Could you please clarify whether the license of this project is intended to be (in SPDX terms)
GPL-3.0-onlyorGPL-3.0-or-later?