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The zlib license [1] is very permissive, so I'm not sure there's any real issue here. [1] https://en.wikipedia.org/wiki/Zlib_License https://en.wikipedia.org/w

The zlib license [1] is very permissive, so I'm not sure there's any real issue here. [1] https://en.wikipedia.org/wiki/Zlib_License https://en.wikipedia.org/wiki/Zlib_License

saagarjha 6y ago
I'm unsure why the tweet author thinks this would be a GPL violation?
- 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).
- deleted 6y ago
  [deleted]
- TonyTrapp 6y ago
  gzip is GPL-licensed. gzip isn't the same as zlib.
  - masklinn 6y ago
    File is imported into gzip from a non-GPL'd project, that gzip is GPL-licensed doesn't relicense the file. File in question literally starts with a comment stating inflate.c -- Not copyrighted 1992 by Mark Adler version c10p1, 10 January 1993
    - monocasa 6y ago
      They can license the changes that they've made to that file since importing as GPL though. The linux copy still includes that header, despite also clearly having GPL code in it as well. Nintendo might have a "I didn't know any better because the header was unclear" argument that might limit their practical damages, but if we can only find this file with associated changes in a GPLed project it certainly looks like GPL infringement.
      - toast0 6y ago
        I mean if the file header says you can do what you want, it seems reasonable to do what you want. If you're relicensing, you should modify or remove that.
        monocasa 6y ago
        If it's had changes since Adler's 1993 copy, then it doesn't matter what Adler says. Grab the original rather than taking code out of GPLed projects if you don't want GPLed code.
bonyt 6y ago
Isn't this post talking about gzip, not zlib?
- deleted 6y ago
  [deleted]
- hinkley 6y ago
  Almost all of the gzip format is the zlib payload. Gzip doesn't even have a data structure for file entries, which is why you gzip tarballs (unlike zip files which have their own file index logic).
clankyclanker 6y ago
Wrong software: the tweeter claims it’s copied from the GPLed Gzip, not zlib. Probably GPLv2, given the release timeline. Man, if copyright wasn’t 85 years long, Nintendo might already be off the hook.
- deleted 6y ago
  [deleted]
- masklinn 6y ago
  > Wrong software: the tweeter claims it’s copied from the GPLed Gzip, not zlib. The tweeter's claim does not matter. If you download the version of gzip they're talking about and look at inflate.c, it clearly spells out that it's authored by Mark Adler free for reuse. The gzip project can not relicense the file, only any addenda they performed to the original might be GPL'd.
  - clankyclanker 6y ago
    Are you certain about that? Wasn’t GPL-relicensing of BSD X-server code part of the original tensions between the GPL and BSD camps? I want to say that was in relation to Gnome, but it’s been a while since I’ve looked for it. Nintendo’s defense, of course, would be to say they received the file from a non-gzip source.
    - lights0123 6y ago
      you can license BSD-licensed files and changes to them as GPL, as BSD is compatible with the GPL as it contains no clause against adding additional restrictions. However, that doesn't magically remove the original license, so you can of course grab the original file and use it under the BSD license.
    - dfox 6y ago
      Assuming that you mean the incident that resulted in the X.org X11 distribution being actually usable for end users it was essentially the other way around. It was about XF86 relicencing originally MIT licensed code under GPL-incompatible license similar to 4-clause BSD.
russdill 6y ago
zlib and gzip are two different source packages with very different licensing.

The zlib license [1] is very permissive, so I'm not sure there's any real issue here. [1] https://en.wikipedia.org/wiki/Zlib_License https://en.wikipedia.org/wiki/Zlib_License

saagarjha 6y ago

I'm unsure why the tweet author thinks this would be a GPL violation?

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).
deleted 6y ago
[deleted]
TonyTrapp 6y ago
gzip is GPL-licensed. gzip isn't the same as zlib.
- masklinn 6y ago
  File is imported into gzip from a non-GPL'd project, that gzip is GPL-licensed doesn't relicense the file. File in question literally starts with a comment stating inflate.c -- Not copyrighted 1992 by Mark Adler version c10p1, 10 January 1993
  - monocasa 6y ago
    They can license the changes that they've made to that file since importing as GPL though. The linux copy still includes that header, despite also clearly having GPL code in it as well. Nintendo might have a "I didn't know any better because the header was unclear" argument that might limit their practical damages, but if we can only find this file with associated changes in a GPLed project it certainly looks like GPL infringement.
    - toast0 6y ago
      I mean if the file header says you can do what you want, it seems reasonable to do what you want. If you're relicensing, you should modify or remove that.
      - monocasa 6y ago
        If it's had changes since Adler's 1993 copy, then it doesn't matter what Adler says. Grab the original rather than taking code out of GPLed projects if you don't want GPLed code.

bonyt 6y ago

Isn't this post talking about gzip, not zlib?

deleted 6y ago
[deleted]
hinkley 6y ago
Almost all of the gzip format is the zlib payload. Gzip doesn't even have a data structure for file entries, which is why you gzip tarballs (unlike zip files which have their own file index logic).

clankyclanker 6y ago

Wrong software: the tweeter claims it’s copied from the GPLed Gzip, not zlib. Probably GPLv2, given the release timeline. Man, if copyright wasn’t 85 years long, Nintendo might already be off the hook.

deleted 6y ago
[deleted]
masklinn 6y ago
> Wrong software: the tweeter claims it’s copied from the GPLed Gzip, not zlib. The tweeter's claim does not matter. If you download the version of gzip they're talking about and look at inflate.c, it clearly spells out that it's authored by Mark Adler free for reuse. The gzip project can not relicense the file, only any addenda they performed to the original might be GPL'd.
- clankyclanker 6y ago
  Are you certain about that? Wasn’t GPL-relicensing of BSD X-server code part of the original tensions between the GPL and BSD camps? I want to say that was in relation to Gnome, but it’s been a while since I’ve looked for it. Nintendo’s defense, of course, would be to say they received the file from a non-gzip source.
  - lights0123 6y ago
    you can license BSD-licensed files and changes to them as GPL, as BSD is compatible with the GPL as it contains no clause against adding additional restrictions. However, that doesn't magically remove the original license, so you can of course grab the original file and use it under the BSD license.
  - dfox 6y ago
    Assuming that you mean the incident that resulted in the X.org X11 distribution being actually usable for end users it was essentially the other way around. It was about XF86 relicencing originally MIT licensed code under GPL-incompatible license similar to 4-clause BSD.

russdill 6y ago

zlib and gzip are two different source packages with very different licensing.