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If a non-profit organization runs software on its website that is modified GPL'ed software and it acknowledged to be such, do they have a legal obligation to release any changes? They are not offering binaries, they're just running it and providing public service. Does it make a difference if the original software was JavaScript (therefore users do acquire source at some point) or PHP? I have already read GNU's opinion, but it is somewhat ambiguous.

marked as duplicate by Jimmy Hoffa, ChrisF Sep 16 '13 at 20:19

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GNU is very clear on that: Under the GPL, you are not legally required to offer the modified source code. The word "legitimate" in the second paragraph of the FAQ entry is a bit misleading, but they rather mean something along the lines of "reasonable, understandable".

There is a special license, the GNU Affero GPL, that handles this question differently:

The GNU Affero General Public License is designed specifically to ensure that, in such cases, the modified source code becomes available to the community.

There you also find a clear note about the normal GPL:

The GNU General Public License permits making a modified version and letting the public access it on a server without ever releasing its source code to the public.

Note: When your application uses GPLed JavaScript libraries, which are delivered to the browser (i.e. not running on the server in node.js or similar), it seems very likely to me (IANAL) that this means "releasing" the software and therefore you must make the source available; this is especially important when your server delivers unreadable minimized JavaScript code.

  • 2
    Or, in layman's terms, you are running the software, not distributing it. – tdammers Jan 30 '12 at 13:30
  • The (new) AGPL Licence addresses this particular issue. – luxcem Jun 23 '14 at 13:09
  • What might this statement from FAQs mean, esp. the second paragraph: But if you release the modified version to the public in some way, the GPL requires you to make the modified source code available to the program's users, under the GPL. Isn't this "releasing the modified version to public in some way"? – Fr0zenFyr Jun 21 '16 at 9:02
  • @Fr0zenFyr: I think releasing has a very clear meaning that doesn't include running it on a server. On the other hand, GPLed JavaScript-Code that does get transported to the user's browser to run there could be seen as "released". – user281377 Jun 21 '16 at 11:56
  • Precisely how I understand it too, I was just hoping to see a mention of javascript in your answer :)... I understand that I can choose to keep the source code on my server for myself with GPL and also that "special" AGPL which restricts you from keeping even the modified code. – Fr0zenFyr Jun 21 '16 at 12:18

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