[Question] Can I modify the license to use AGPL as the future license instead of MIT/Apache 2.0?

[Orenoid]

I'm new to software licensing, sorry if I ask any stupid questions.

I'm currently developing a product and would like to apply the Fair Source License.
However, I'm reluctant to switch to MIT or Apache 2.0 after the initial period, so I modified the license terms to use AGPL as the future license in my LICENSE file.

Is this modification legally valid and effective?

[voxpelli]

I think #49 (comment) and #46 can provide some insight

[ljharb]

tldr, no, the point of FSL is that it ends up free after the time period. If you want AGPL, you should start with AGPL.

[mon-jai]

Isn't AGPL free too?

[Orenoid]

I think #49 (comment) and #46 can provide some insight

Thanks, I should've checked them, sorry about that. I guess the answer is no then, since copyleft licenses are not acceptable.

If I still would like to apply AGPL after 2 years, given that it no longer meet the requirements of Fair Source License, should I rename the license to something else? Or is renaming not even an option and I have to adopt some other entirely different license?

[Orenoid]

tldr, no, the point of FSL is that it ends up free after the time period. If you want AGPL, you should start with AGPL.

Sorry, I'm a bit confused. As @mon-jai mentioned, AGPL is also free, except it's copyleft. So I believe it doesn't conflict with the 「free」requirements.

[mon-jai]

except it's copyleft

Copyleft licenses are considered free by both FSF and OSI.

[gavin-zee]

FSL was drafted with the specific intent of converting into permissive open source licenses (not copyleft), because permissive licenses aligned most closely with how we ideally wanted to license our own products when converting. We also wanted to avoid license proliferation, which in our view was one of the biggest downsides of the BUSL. Because any change license could be designated under the BUSL, it made it very difficult from a compliance perspective, as each version was different.

TLDR, FSL is narrow in scope for a reason.

You're free to create your own license based on the FSL with AGPL as the change license if you rename it so that it isn't confusingly similar.

[voxpelli]

since copyleft licenses are not acceptable

No other licenses than MIT and Apache2 are acceptable when it comes to FSL.

Regarding AGPL in particular though, fsl.software says this:

What about AGPLv3 though?
AGPLv3 is not permissive enough. As a highly viral copyleft license, it exposes users to serious risk of having to divulge their proprietary source code. FSL does not introduce this risk, so FSL software can be adopted at organizations where AGPL is outside of policy.

Notable is also that FSL's immediate predecessor, the Business Source License (BSL or BUSL), allows one to customize the license more, and one can eg. pretty much configure it to be identical to FSL. Its restrictions on licenses are (with my emphasiz):

GPL Version 2.0 or any later version, or a license that is compatible with GPL Version 2.0 or a later version, where “compatible” means that software provided under the Change License can be included in a program with software provided under GPL Version 2.0 or a later version.

Since you can't include AGPLv3 code in a program with software provided under GPL Version 2.0 or a later version – BSL doesn't allow AGPLv3 either, despite allowing / defaulting to a copyleft license.

Edit: One can do some odd linking of with GPLv3 and AGPLv3 due to some special writing in the licenses, but the result will not really be fully GPLv3 licensed: https://www.gnu.org/licenses/agpl-3.0.html#section13

[voxpelli]

You're free to create your own license based on the FSL with AGPL as the change license if you rename it so that it isn't confusingly similar.

@gavin-zee What's the license of the FSL license?

Eg. BSL says In consideration of the right to use this License’s text [...] Not to modify this License in any other way. in the Covenants of Licensor at https://mariadb.com/bsl11/

Also the FSF has some wordings in regards to modifying the GPL licenses: https://www.gnu.org/licenses/gpl-faq.html#ModifyGPL

Maybe the FSL should also have some wording? And since the FSL is narrow in scope for a reason, it would probably be better for most who feel its too narrow to use the BSL rather than fork the FSL license? Should probably be added to the FAQ as well?

[gavin-zee]

@voxpelli we wanted to keep the FSL simple so we avoided the license the license language. That said, we can consider addressing in the FAQs since this question of changes to the license has come up a few times now. (cc @chadwhitacre)

[voxpelli]

At a minimum I think it should say that when using the FSL name no modifications are allowed

[Orenoid]

Based on the discussion above, I assume I should rename the license to differentiate it from FSL then.
Thanks for all the clarification and help. Feel free to close the issue.

[chadwhitacre]

consider addressing in the FAQs
At a minimum I think it should say that when using the FSL name no modifications are allowed

Is #54 good enough?

[voxpelli]

With the addition from #54 I think this issue is answered and can be closed