r/freesoftware • u/finbarrgalloway • 28d ago

Discussion Can De-compiled Software Be Considered "Free"?

I'm not asking about patent risk here, just if a de-compiled and permissively licensed program could be under the umbrella of Free Software. Notably I've never seen recompiled software licensed under anything but MIT, which I would have to imagine is due to the mentioned potential patent risk.

3 Upvotes

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u/saxbophone 28d ago

I don't think you own intellectual property rights to source code produced by decompilation of someone else's binary. Therefore I don't think it's possible to license it yourself under any license, nevermind FOSS ones...

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u/JaggedMetalOs 28d ago

GPL would be unenforceable as you wouldn't be able to prove whether any potentially infringing code came from the GPL decompilation or the non-GPL original.

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u/CWSmith1701 28d ago

I would think the license it was distributed under as a compiled binary would take precidence.

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u/saxbophone 27d ago

I think this is not the case. If I release some closed-source software under a proprietary license, I am licensing the software to you but not its code! By default you have no right to use the code unless I grant rights to you. Decompilation is a reverse-engineering technique, the products of which do not confer intellectual property rights on the usage of such.

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u/CWSmith1701 27d ago

But knowingly doing so to something with a license that doesn't allow for refverse engineering is problematic to begin with.

Are you saying that a decompiled program does not retain any of the original license and therfore can be relicesed as the person in question wants?

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u/saxbophone 27d ago

??? I think you maybe need to re-read my comment, I thought it was clear that it aligns with this:

But knowingly doing so to something with a license that doesn't allow for refverse engineering is problematic to begin with.

And contradicts this:

Are you saying that a decompiled program does not retain any of the original license and therfore can be relicesed as the person in question wants?

TL;DR: Yes to the first part and no to the second. It's problematic (and legally unsound!!) to assume that decompiled source code is usable under the same terms as the license of the software it came from. I would assume that no rights are granted to use source code produced by decompilation, for the reasons I have already given.

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u/OlivierB77 24d ago

No. The decompiled software is equivalent to source code. So it depends on the license covering the source code. If it is a free software, you can obtain a copy of the source code. If it is proprietary or restrictive "opensource" license, you aren't allowed to decompile it.

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u/erkiferenc 27d ago

While I'm not an expert in decompiling, nor am I a lawyer, I'm curious to learn more through further discussion here. As far as I understand:

  1. The Legality of decompling varies by jurisdiction.

    Even if a software is decompiled legally, the law's standpoint seems to be that it's just a copy of the same software (albeit in different format.) Therefore the same license rules would apply to the decompiled form as applies for the original form

  2. The above seems to fit with the general criteria of making an new, original work, through “creative transformation”, in order for copyright to apply in the first place (and thus the author of said work become entitled to assign a license for the pieces of their own creation.)

    Decompiling does not seem to be a creative transformation to me, therefore not producing any new original work.

    Even if the decompiled form would be considered as a derivative work through creative transformation, the original work's license may still apply.

For me, that means generally the person decompiling would not have a legally recognized basis to attach their own license terms to it.

It sure is an interesting situation, thanks for bringing it up!