In accordance with Section 7(b) of the GNU Affero General Public License, you must retain the producer line in every PDF that is created or manipulated using iText.
That didn't really meet my understanding of section 7(b), so I asked the Free Software Foundation for a clarification:
I read that portion of the license and it says:
Notwithstanding any other provision of this License, for material you
add to a covered work, you may (if authorized by the copyright holders of
that material) supplement the terms of this License with terms:
b) Requiring preservation of specified reasonable legal notices or
author attributions in that material or in the Appropriate Legal
Notices displayed by works containing it;
I would understand “that material” to be the source code, and they can require retaining the author attributions and legal notices in their source code. However a restrictions that says you cannot change how the source code performs its function, or require that it put specific text in an output result of the software would seem to not be authorized by section b, and it would seem to violate the letter and spirit of the AGPL. Can you please clarify?
Thank you very much.
Francois Marier was kind enough to get back to me and replied:
Section 7(b) allows you to add either or both of two separate things.
First is "Requiring preservation of specified reasonable legal notices or author attributions in that material" -- and you're right that "that material" here is source code that you add to the software (per the paragraph at the top of the list in section 7). So the requirement in question does not meet that criteria.
The second thing it allows you to add is a requirement to add similar text "in the Appropriate Legal Notices displayed by works containing it." This goes beyond the source code: per the definition of Appropriate Legal Notices in section 0, these appear in interactive user interfaces provided by the software. However, that still doesn't go so far as including notices in the noninteractiveoutput of the program. So the requirement does not meet this criteria either, and is not acceptable under section 7(b).
Please note that this is not legal advice.
So given the above if you were a company that had a business model that would involve distributing AGPL software, and you wanted to use something from some other Vendor plus iText, you would have a real problem. On the one hand, iText is giving you a non-AGPL compliant license restriction, on the other hand, it is their code, they can do that if they want to. Even if the FSF has a problem with taking and modifying the AGPL for your own purposes, that would be between iText and them, it would not automatically entitle you to use iText under a pure AGPL. Maybe you could make that case in court, but who would want to take that chance?
So the bottom line is that the ability to add restrictions of a limited type, coupled with the inability to add further restrictions can take the whole GPL/AGPL license into a host of incompatibilities. I hope the FSF figures out a better solution for the next version.