7 ms·

Comparison of open-source licenses

78 points by e1ven 15y ago

e1ven 15y ago
After reading through an absurd number of licenses, this is my understanding of the way various things combine. I'm sure the HN community has people smarter than I, who will immediately see some mistake I may have made. Thank you! In that event, I shall issue a correction post-haste.
- 0x09 15y ago
  I'm not clear on the criteria you used for the web-apps column. The LGPL and GPL are listed as applying differently, but to my understanding both are equally agnostic to network use compared with something like the AGPL.
  - e1ven 15y ago
    Thanks. I think I must have flipped something when creating the table. I was copying each row above it, and editing. I must have forgotten to flip that. Fixed.Thanks.
- HerraBRE 15y ago
  I think you may have an error in the AGPLv3 description, where you say "No" in the "Web Apps" column.
jmillikin 15y ago
"""Licenses that use Copyleft are sometimes called “Viral” licenses; If you include any code that uses that license in your code, then your entire program has to be released under the same license.""" This claim is often made (especially by corporate interests who dislike reciprocal licenses), but it is not true. The only major reciprocal licenses, the GPL and LGPL, do not require that the entire codebase be under the GPL/LGPL. It only has to be under a compatible license. For example, say I had a 10,000-line BSD-licensed application, and I copied a few hundred lines of some GPL'd code into it, then: * The original code is still BSD licensed. * The copied code is still GPL'd. * The source tarball must include both license documents. * The compiled binary must be distributed in a way complying with both licenses. In particular, someone may download the BSD+GPL source, remove the GPL'd part, compile what's left, and distribute the resulting binaries without source. The licensing situation of the BSD'd code has not been changed in any way! ----------- The "Weak" and "Strong" copylefts you describe don't make much sense, either. Both GPL and LGPL code can have proprietary products use them. The primary difference is that proprietary binaries may directly include LGPL'd code, but GPL'd code can't be included in proprietary applications. For example, consider a proprietary application that dynamically links against "readline". Depending on which libraries are installed on the end user's machine, at runtime one of these will happen: * The application tries to load libreadline.so, fails, and continues to run (perhaps disabling some advanced functionality). * The application loads libreadline.so, which is a compiled library for readline (a GPL-licensed library). * The application loads libreadline.so, which is a compiled library for editline (a BSD-licensed replacement for readline). Obviously, the proprietary application is "using" readline, but as it's not distributed with any readline code, the authors of the application do not need any copyright permission from the readline authors. An interesting variant if the original application binary was compiled on a system that had editline installed. From proprietary application developer's point of view, they used only BSD-licensed software, and didn't even distribute third-party code, so why should the GPL matter at all? The major "grey area" here is GPL'd code, as a shared library, bundled with a proprietary application as a fallback in case the end user's system doesn't have it installed. While I think that this would be OK in most situations (assuming the library's API is intact), it's murky enough that the application author should check with a copyright lawyer first. ----------- Regarding "web application" licenses, note that regardless of what they claim, they do not (and cannot) apply unless you're distributing the software. Remember, they're still just copyright licenses. If you're not doing anything that requires copyright permission, you do not have to obey them. For example, if someone writes an AGPL'd application that generates an image of the Mandelbrot set, I can install that application on my server and have it send images to users without distributing the source. The only area where AGPL-style licenses are relevant is when running the application requires distributing part of it to users. Think of html page templates, or Javascript.
- bunderbunder 15y ago
  The only major reciprocal licenses, the GPL and LGPL, do not require that the entire codebase be under the GPL/LGPL. It only has to be under a compatible license. From many software vendors' perspective, this is a difference without much distinction. The salient point to them is, if GPL code sneaks into their codebase then they might be forced to switch to a permissive software license, and that might be very disruptive to their business. And it does manage to have a chilling effect in some industries. In the one I work in, for example, there is a prevailing culture of outright fear of open source software, including of supposedly "business-compatible" code. The worry is that it's hard to trace the provenance of all code, which makes it difficult to dismiss the possibility that, e.g., ostensibly MIT-licensed code is actually GPL-licensed. The fear is perhaps far too great, but from the decisionmakers' perspective this is a situation where their livelihood is potentially at stake, and many of them would rather pay to develop 100% proprietary software than risk getting infected with open-source cooties.
  - __alexs 15y ago
    When you say "chilling effect" are you suggesting that entire industries are being held back by the existence of the GPL? This seems similar to calling Android "the greatest legal destruction of wealth in history." (http://gizmodo.com/5785983/android-may-be-the-greatest-legal-destruction-of-wealth-in-history http://gizmodo.com/5785983/android-may-be-the-greatest-legal...)
    - bunderbunder 15y ago
      To say that entire industries are being held back by their fears about the GPL would be closer to what I was getting at. And not in a way that has anything to do with what Mr. Gurley was claiming. What I'm more worried about is the opportunity to fund innovation that is lost when companies choose to sink resources into reinventing wheels rather than picking open source projects off the shelf.
      - mkup 15y ago
cobrausn 15y ago
No WTFPL? For shame. http://sam.zoy.org/wtfpl/ http://sam.zoy.org/wtfpl/
- pjscott 15y ago
  The WTFPL doesn't really need explaining. The terms of the license ("You just DO WHAT THE FUCK YOU WANT TO") are shorter than most licenses' summaries.
draegtun 15y ago
Complete list of OSI approved licenses: http://www.opensource.org/licenses/alphabetical http://www.opensource.org/licenses/alphabetical
jasonlotito 15y ago
An error in your table lists AGPL 3 as not applying to the web.
sateesh 15y ago
Also there is a wiki page which compares various open source licenses: http://en.wikipedia.org/wiki/Comparison_of_free_and_open_source_software_licenses http://en.wikipedia.org/wiki/Comparison_of_free_and_open_sou...
skrebbel 15y ago
i miss the lovely and extremely liberal zlib/libpng license. in short "here's the code, don't sue us".
- e1ven 15y ago
  Wouldn't the MIT/X11 license be a good choice for this situation? It's fairly liberally used, permissive, and has a similar anti-endorsement clause.
  - skrebbel 15y ago
    Main difference is that the zlib license does not require you to ship the copyright from non-source distributions. It's essentially "I don't need credit, as long as you don't say you made it yourself".

78 points by e1ven 15y ago

e1ven 15y ago

After reading through an absurd number of licenses, this is my understanding of the way various things combine. I'm sure the HN community has people smarter than I, who will immediately see some mistake I may have made. Thank you! In that event, I shall issue a correction post-haste.

0x09 15y ago
I'm not clear on the criteria you used for the web-apps column. The LGPL and GPL are listed as applying differently, but to my understanding both are equally agnostic to network use compared with something like the AGPL.
- e1ven 15y ago
  Thanks. I think I must have flipped something when creating the table. I was copying each row above it, and editing. I must have forgotten to flip that. Fixed.Thanks.
HerraBRE 15y ago
I think you may have an error in the AGPLv3 description, where you say "No" in the "Web Apps" column.

jmillikin 15y ago

"""Licenses that use Copyleft are sometimes called “Viral” licenses; If you include any code that uses that license in your code, then your entire program has to be released under the same license.""" This claim is often made (especially by corporate interests who dislike reciprocal licenses), but it is not true. The only major reciprocal licenses, the GPL and LGPL, do not require that the entire codebase be under the GPL/LGPL. It only has to be under a compatible license. For example, say I had a 10,000-line BSD-licensed application, and I copied a few hundred lines of some GPL'd code into it, then: * The original code is still BSD licensed. * The copied code is still GPL'd. * The source tarball must include both license documents. * The compiled binary must be distributed in a way complying with both licenses. In particular, someone may download the BSD+GPL source, remove the GPL'd part, compile what's left, and distribute the resulting binaries without source. The licensing situation of the BSD'd code has not been changed in any way! ----------- The "Weak" and "Strong" copylefts you describe don't make much sense, either. Both GPL and LGPL code can have proprietary products use them. The primary difference is that proprietary binaries may directly include LGPL'd code, but GPL'd code can't be included in proprietary applications. For example, consider a proprietary application that dynamically links against "readline". Depending on which libraries are installed on the end user's machine, at runtime one of these will happen: * The application tries to load libreadline.so, fails, and continues to run (perhaps disabling some advanced functionality). * The application loads libreadline.so, which is a compiled library for readline (a GPL-licensed library). * The application loads libreadline.so, which is a compiled library for editline (a BSD-licensed replacement for readline). Obviously, the proprietary application is "using" readline, but as it's not distributed with any readline code, the authors of the application do not need any copyright permission from the readline authors. An interesting variant if the original application binary was compiled on a system that had editline installed. From proprietary application developer's point of view, they used only BSD-licensed software, and didn't even distribute third-party code, so why should the GPL matter at all? The major "grey area" here is GPL'd code, as a shared library, bundled with a proprietary application as a fallback in case the end user's system doesn't have it installed. While I think that this would be OK in most situations (assuming the library's API is intact), it's murky enough that the application author should check with a copyright lawyer first. ----------- Regarding "web application" licenses, note that regardless of what they claim, they do not (and cannot) apply unless you're distributing the software. Remember, they're still just copyright licenses. If you're not doing anything that requires copyright permission, you do not have to obey them. For example, if someone writes an AGPL'd application that generates an image of the Mandelbrot set, I can install that application on my server and have it send images to users without distributing the source. The only area where AGPL-style licenses are relevant is when running the application requires distributing part of it to users. Think of html page templates, or Javascript.

bunderbunder 15y ago
The only major reciprocal licenses, the GPL and LGPL, do not require that the entire codebase be under the GPL/LGPL. It only has to be under a compatible license. From many software vendors' perspective, this is a difference without much distinction. The salient point to them is, if GPL code sneaks into their codebase then they might be forced to switch to a permissive software license, and that might be very disruptive to their business. And it does manage to have a chilling effect in some industries. In the one I work in, for example, there is a prevailing culture of outright fear of open source software, including of supposedly "business-compatible" code. The worry is that it's hard to trace the provenance of all code, which makes it difficult to dismiss the possibility that, e.g., ostensibly MIT-licensed code is actually GPL-licensed. The fear is perhaps far too great, but from the decisionmakers' perspective this is a situation where their livelihood is potentially at stake, and many of them would rather pay to develop 100% proprietary software than risk getting infected with open-source cooties.
- __alexs 15y ago
  When you say "chilling effect" are you suggesting that entire industries are being held back by the existence of the GPL? This seems similar to calling Android "the greatest legal destruction of wealth in history." (http://gizmodo.com/5785983/android-may-be-the-greatest-legal-destruction-of-wealth-in-history http://gizmodo.com/5785983/android-may-be-the-greatest-legal...)
  - bunderbunder 15y ago
    To say that entire industries are being held back by their fears about the GPL would be closer to what I was getting at. And not in a way that has anything to do with what Mr. Gurley was claiming. What I'm more worried about is the opportunity to fund innovation that is lost when companies choose to sink resources into reinventing wheels rather than picking open source projects off the shelf.
    - mkup 15y ago

cobrausn 15y ago

No WTFPL? For shame. http://sam.zoy.org/wtfpl/ http://sam.zoy.org/wtfpl/

pjscott 15y ago
The WTFPL doesn't really need explaining. The terms of the license ("You just DO WHAT THE FUCK YOU WANT TO") are shorter than most licenses' summaries.

draegtun 15y ago

Complete list of OSI approved licenses: http://www.opensource.org/licenses/alphabetical http://www.opensource.org/licenses/alphabetical

jasonlotito 15y ago

An error in your table lists AGPL 3 as not applying to the web.

sateesh 15y ago

Also there is a wiki page which compares various open source licenses: http://en.wikipedia.org/wiki/Comparison_of_free_and_open_source_software_licenses http://en.wikipedia.org/wiki/Comparison_of_free_and_open_sou...

skrebbel 15y ago

i miss the lovely and extremely liberal zlib/libpng license. in short "here's the code, don't sue us".

e1ven 15y ago
Wouldn't the MIT/X11 license be a good choice for this situation? It's fairly liberally used, permissive, and has a similar anti-endorsement clause.
- skrebbel 15y ago
  Main difference is that the zlib license does not require you to ship the copyright from non-source distributions. It's essentially "I don't need credit, as long as you don't say you made it yourself".