Change license from LGPL 2.1 to MIT ?

[PowerKiKi]

From what I understand, notably from a similar move from jQuery, it would technically be legal to change our license from LGPL to MIT. The reasons for such a move would to get rid of the boilerplate header in all files (which is not always consistent in our case), and make the end-user life easier by choosing a well-known, very permissive and broadly used license.

But I am not a lawyer, and I may be missing something. Is it really doable ? is there anything else to do than edit the files ? should we contact previous contributors ?

@MarkBaker, @maartenba as the two most prominent contributors, would you have any opinion on the matter ?

Also @Progi1984 what was the rationale for choosing LGPL 3 for PhpWord ? I see it was talked about in PHPOffice/PHPWord#211, but would your mind has changed in the last 3 years ?

[maartenba]

I for one am open to going for a more permissive license. Back when I started this thing ten years ago, LGPL was the license many chose, but since the world has changed a lot.

[PowerKiKi]

Thanks for your input. Would you know anything about how we should do it ?

[maartenba]

@MarkBaker @Progi1984 what do you think? Should we go to a different license?

[lanthaler]

+1 for MIT

[m8e]

+1 MIT, then I will be allowed to use PHPSpreadsheet at my daytime job :-)

[PowerKiKi]

Mark confirmed via Twitter that he agreed to switch to MIT, so we can go ahead with this as soon as #147 is merged.

[maartenba]

Nice!

[Croydon]

jQuery's situation was different since they already did dual-licensing under GPL and MIT and they simply dropped GPL for any further versions.

PhpSpreadsheet is not dual-licensed and you want to change the license in a not compatible way. More permissive licenses are after compatible with more restrictive licenses, but not the other way around.

You either need to ask every single contributor to relicense their contribution or you need to remove their contribution (replacing it with something new) or you can't change from GPL to MIT without violating the rights of the contributors.

You could start adding a checkbox to your pull request template asking new contributors to dual-license under LGPL and MIT, then starting to contact previous contributors and/or rewriting smaller contributions.

Once done you can drop LGPL and move to MIT.

[PowerKiKi]

@Croydon do you have any source for that? Maybe specific extract of some license?

It sounds likely but I'd rather be as sure as possible before doing something either way. Also I am not sure whether getting a reply from every single contributors is actually possible :-/

[PowerKiKi]

@maartenba (and @MarkBaker), I had a look for this license change and stumbled upon the BIFF writing part (now living in PhpOffice\PhpSpreadsheet\Writer\Xls) which was originally taken from Spreadsheet_Excel_Writer a long time ago. The files still have a header mentioning the original license which was LGPL 2.1.

I am unsure what to do with those. Should the original header be deleted, assuming the code was heavily modified by you when it was integrated ? Or should we keep it intact, meaning that the project would have a mix of MIT and LGPL files ?

For some minor, sporadic contributions from random contributor I may imagine making a leap of faith and changing the license "juste like that", but for this kind of case, where an important part of this project is concerned, I am much less sure on what to do.

Do you have any advice on the matter ? Maybe you had some kind of agreement way back when you integrated that project into PHPExcel ? Or would you have any contact with maintainer of back then ?

[PowerKiKi]

There actually is a similar case for PhpOffice\PhpSpreadsheet\Shared\OLE things which licensed under the PHP license 2.02. Any opinion on what to do with that ?

[m8e]

@PowerKiKi for the LGPL being included as a library license (for BIFF writing), it should NOT affect the MIT status of the overall project, iff nobody ever modify the LGPL code of the included library. Because quoting the LGPL:

---

"A program that contains no derivative of any portion of the Library, but is designed to work with the Library by being compiled or linked with it, is called a "work that uses the Library". Such a work, in isolation, is not a derivative work of the Library, and therefore falls outside the scope of this License."

---

Maybe same for PHP license?

[m8e]

Also here is a project that moved forwards from LGPL to MIT and asked all the major contributors to publicly agree in the disussion thread they are happy to modify the license to MIT for the ongoing future versions

gtk-rs/gtk#20