4 ms·

Is this zlib source code or gzip source code? gzip is GPL isn't it? Also, if this is GPL code, does that mean Dr. Mario would need to be licensed under the GPL

by gfodor 6y ago

Is this zlib source code or gzip source code? gzip is GPL isn't it? Also, if this is GPL code, does that mean Dr. Mario would need to be licensed under the GPL? And would that mean any other distributed software by Nintendo which uses any code from Dr. Mario 64 would need to be licensed under the GPL? If so, isn't that... kind of a big deal?

masklinn 6y ago
gzip is GPL but zlib is not. However since zlib's license is GPL-compatible it's just fine to e.g. vendor zlib inside gzip. That does not make it gzip code, the zlib code is not relicensed and it keeps its original license. Furthermore, both gzip and DrMario64 having merged in zlib's code does not give gzip any claim upon DrMario64.
- gfodor 6y ago
  That wasn't my question, my question was if the posted code is from gzip or zlib. It looks like it's probably zlib.
  - masklinn 6y ago
    > That wasn't my question But it's the answer. > my question was if the posted code is from gzip or zlib. It looks like it's probably zlib. It's zlib code living inside gzip, so it's not an either / or question.
    - gfodor 6y ago
      The question I am asking is the code posted "zlib code living inside of gzip" or "gzip code that has nothing to do with zlib." The decompression code posted may be in gzip proper, but probably not. I haven't seen anyone post the zlib source in this thread proving so. edit: I see you've answered this in another thread. Thanks.
- duckerude 6y ago
  Does gzip actually use zlib? zlib's implementation (https://github.com/madler/zlib/blob/v1.1.3/inflate.c https://github.com/madler/zlib/blob/v1.1.3/inflate.c) looks different at first glance, gzip predates it by three years, and I believe gzip is also noticeably slower.
  - masklinn 6y ago
    > Does gzip actually use zlib? If you go and download gzip 1.2.4a (the version mentioned) and open it, the first two lines state: /* inflate.c -- Not copyrighted 1992 by Mark Adler version c10p1, 10 January 1993 */ Note that the file you link to is copyrighted (rather than not-copyrighted) 1995-1998. Now maybe saying that it's zlib's is inexact because zlib did not actually exist at the time, but that doesn't really make a difference, it's basically the code to what would eventually become zlib, by zlib's author, under a hyper-permissive license.
    - duckerude 6y ago
      Saying it's zlib's did confuse me. But I think I understand now, thank you.
lolc 6y ago
Well only the code that was published with GPL'd code compiled in would have to be made available under the GPL. As Nintendo presumably has copyright on the other parts and can publish them however they want. Unless there are more surprises.
- gfodor 6y ago
  If I release two pieces of software, one GPL, and another closed source which uses some of my GPLed code, if someone discovers the closed source one uses that code am I obligated to apply the GPL’s terms to the other project?
  - lolc 6y ago
    You can offer your code under as many licences as you want. So you can publish the same code under both GPL and a proprietary license. This is called dual-licensing. The people that receive the code from you under one of those licences will not have that liberty. They will have to abide to the licence you gave them. For proprietary licences, that usually means they are not allowed to do more than use it. For GPL, that means they can pass it on under the GPL. So in your example, while people could share the code you publish under the GPL, it does not impact what you can do with your closed source version. Only when you'd start to integrate patches to the GPL branch from third parties, you'd get into trouble.
klyrs 6y ago
I don't think it's that virulent. If Nintendo releases Dr Mario under GPL, they could compel themselves to also release derivative works. But I don't think anybody else would have the standing (unless those works also contain gzip or other GPL code)
- gfodor 6y ago
  why wouldn't consumers have the standing, given that the GPL grants them rights to read source code of or create derivative works of the products they purchased if the code is GPL?
  - masklinn 6y ago
    Because it's code released by Mark Adler which gzip uses and: 1. there's no evidence so far that Nintendo didn't just independently use the same release 2. that gzip uses it doesn't relicense the file
    - gfodor 6y ago
      I wasn’t asking in this scenario but in general if a game company was forced to retroactively license a game under the GPL
      - klyrs 6y ago
        Note: this comment is written under the assumption that Nintendo included GPL'd code, which doesn't appear to be the case. But this is an interesting hypothetical either way. The answers here are in line with my (NAL) understanding of the issue: https://softwareengineering.stackexchange.com/questions/331846/dual-license-with-gpl-and-a-closed-source-license https://softwareengineering.stackexchange.com/questions/3318... If the Nintendo-authored derivatives of Dr. Mario are free of external GPL code; more generally, if they are the sole copyright holders of those derivatives -- they may release them (or not) under any license they like. For instance, you're welcome to release a work under GPL, and maintain a proprietary patchset that you release only in binary form. But, at the moment that you incorporate code/content written by external contributors under the GPL license, you cannot incorporate that into your proprietary version. While Nintendo may not be compelled to release derivatives, it is my (NAL) understanding that the gzip authors would have a very strong case to a very expensive discovery process which would provide them very broad access to Nintendo's game source code. While I don't think that all of the revealed code would enter public record, some of it would inevitably be entered as evidence. There's another fun case worthy of consideration: if you are the sole author of some body of code, and you contribute that code to a GPL-licensed project (but do not assign copyright to that project), you retain full rights to the original code. You may, at a later date, license the original form of that code to an employer for proprietary use, or to another project using an incompatible license. And this is a great use of version control software -- you must not include later improvements to that code that was made by others; and the repo provides excellent historical evidence.
tialaramex 6y ago
No, it's just copyright infringement, it doesn't magically relicense other people's work. In theory the publishers of Dr Mario might owe the copyright holders for GNU zip (perhaps the FSF) damages, and of course it would be possible to stop them from shipping more copies of the infringing product, Dr Mario (I doubt this is a real issue since it's an old game).

by gfodor 6y ago

masklinn 6y ago

gzip is GPL but zlib is not. However since zlib's license is GPL-compatible it's just fine to e.g. vendor zlib inside gzip. That does not make it gzip code, the zlib code is not relicensed and it keeps its original license. Furthermore, both gzip and DrMario64 having merged in zlib's code does not give gzip any claim upon DrMario64.

gfodor 6y ago
That wasn't my question, my question was if the posted code is from gzip or zlib. It looks like it's probably zlib.
- masklinn 6y ago
  > That wasn't my question But it's the answer. > my question was if the posted code is from gzip or zlib. It looks like it's probably zlib. It's zlib code living inside gzip, so it's not an either / or question.
  - gfodor 6y ago
    The question I am asking is the code posted "zlib code living inside of gzip" or "gzip code that has nothing to do with zlib." The decompression code posted may be in gzip proper, but probably not. I haven't seen anyone post the zlib source in this thread proving so. edit: I see you've answered this in another thread. Thanks.
duckerude 6y ago
Does gzip actually use zlib? zlib's implementation (https://github.com/madler/zlib/blob/v1.1.3/inflate.c https://github.com/madler/zlib/blob/v1.1.3/inflate.c) looks different at first glance, gzip predates it by three years, and I believe gzip is also noticeably slower.
- masklinn 6y ago
  > Does gzip actually use zlib? If you go and download gzip 1.2.4a (the version mentioned) and open it, the first two lines state: /* inflate.c -- Not copyrighted 1992 by Mark Adler version c10p1, 10 January 1993 */ Note that the file you link to is copyrighted (rather than not-copyrighted) 1995-1998. Now maybe saying that it's zlib's is inexact because zlib did not actually exist at the time, but that doesn't really make a difference, it's basically the code to what would eventually become zlib, by zlib's author, under a hyper-permissive license.
  - duckerude 6y ago
    Saying it's zlib's did confuse me. But I think I understand now, thank you.

lolc 6y ago

Well only the code that was published with GPL'd code compiled in would have to be made available under the GPL. As Nintendo presumably has copyright on the other parts and can publish them however they want. Unless there are more surprises.

gfodor 6y ago
If I release two pieces of software, one GPL, and another closed source which uses some of my GPLed code, if someone discovers the closed source one uses that code am I obligated to apply the GPL’s terms to the other project?
- lolc 6y ago
  You can offer your code under as many licences as you want. So you can publish the same code under both GPL and a proprietary license. This is called dual-licensing. The people that receive the code from you under one of those licences will not have that liberty. They will have to abide to the licence you gave them. For proprietary licences, that usually means they are not allowed to do more than use it. For GPL, that means they can pass it on under the GPL. So in your example, while people could share the code you publish under the GPL, it does not impact what you can do with your closed source version. Only when you'd start to integrate patches to the GPL branch from third parties, you'd get into trouble.

klyrs 6y ago

I don't think it's that virulent. If Nintendo releases Dr Mario under GPL, they could compel themselves to also release derivative works. But I don't think anybody else would have the standing (unless those works also contain gzip or other GPL code)

gfodor 6y ago
why wouldn't consumers have the standing, given that the GPL grants them rights to read source code of or create derivative works of the products they purchased if the code is GPL?
- masklinn 6y ago
  Because it's code released by Mark Adler which gzip uses and: 1. there's no evidence so far that Nintendo didn't just independently use the same release 2. that gzip uses it doesn't relicense the file
  - gfodor 6y ago
    I wasn’t asking in this scenario but in general if a game company was forced to retroactively license a game under the GPL
    - klyrs 6y ago
      Note: this comment is written under the assumption that Nintendo included GPL'd code, which doesn't appear to be the case. But this is an interesting hypothetical either way. The answers here are in line with my (NAL) understanding of the issue: https://softwareengineering.stackexchange.com/questions/331846/dual-license-with-gpl-and-a-closed-source-license https://softwareengineering.stackexchange.com/questions/3318... If the Nintendo-authored derivatives of Dr. Mario are free of external GPL code; more generally, if they are the sole copyright holders of those derivatives -- they may release them (or not) under any license they like. For instance, you're welcome to release a work under GPL, and maintain a proprietary patchset that you release only in binary form. But, at the moment that you incorporate code/content written by external contributors under the GPL license, you cannot incorporate that into your proprietary version. While Nintendo may not be compelled to release derivatives, it is my (NAL) understanding that the gzip authors would have a very strong case to a very expensive discovery process which would provide them very broad access to Nintendo's game source code. While I don't think that all of the revealed code would enter public record, some of it would inevitably be entered as evidence. There's another fun case worthy of consideration: if you are the sole author of some body of code, and you contribute that code to a GPL-licensed project (but do not assign copyright to that project), you retain full rights to the original code. You may, at a later date, license the original form of that code to an employer for proprietary use, or to another project using an incompatible license. And this is a great use of version control software -- you must not include later improvements to that code that was made by others; and the repo provides excellent historical evidence.

tialaramex 6y ago

No, it's just copyright infringement, it doesn't magically relicense other people's work. In theory the publishers of Dr Mario might owe the copyright holders for GNU zip (perhaps the FSF) damages, and of course it would be possible to stop them from shipping more copies of the infringing product, Dr Mario (I doubt this is a real issue since it's an old game).