I do not quite understand what "user-visible display" in the following sentence in RPL (https://opensource.org/licenses/RPL-1.5) means:

d. User-Visible Attribution. You must duplicate any notice contained in EXHIBIT B (the "User-Visible Attribution Notice") in each user-visible display of the Licensed Software and Your Extensions which delineates copyright, ownership, or similar attribution information.

The RPL-covered "Licensed Software" I intend to use is a library given in form of a source code. My product would not redistribute the source code, the "Licensed Software" will be compiled into it and become "unseparable" from the rest of it. The "Licensed Software" provides some communication protocol functionality and is effectively hidden under multiple layers of other code. As far as I understand I am not creating extensions to it, so I believe that I have no "user-visible display of Your Extensions". (It is also interesting to note that "Your Extensions" are not defined anywhere in the license text).

In this case, do I have any "user-visible" display of the Licensed Software? Or is "user-visible display" intended to include indirect effects of using the Licensed Software - which is manifested only by the fact that my software would have some features that otherwise would not work?

  • 1
    Does the library you are using actually specify a notice for the EXHIBIT B section of the license? On the template you have shown, that is at the very bottom. The author should presumably write something after the first ":" contained in EXHIBIT B, otherwise it can be treated as blank (no notice). I know it's not really an answer, but if that part is blank, then at least for your case, you can ignore this issue as non-relevant for the library you are using.
    – Brandin
    Commented Mar 16, 2018 at 11:59
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    @Brandin: Yes, there is a notice under EXHIBIT B.
    – ZbynekZ
    Commented Mar 16, 2018 at 15:30
  • As far as I can tell, the "user-visible display [...] which delineates copyright, ownership, or similar attribution information" refers to what is commonly known as an "about"-screen/dialog. Also note that the RPL seems to be intended to be an even stronger copyleft license than the GPL. Commented Mar 16, 2018 at 16:00
  • "each user-visible display" seems to imply multiple possible such displays. Not a very good license if it is so hard to use.
    – Brandin
    Commented Mar 16, 2018 at 19:11

1 Answer 1


"Extensions" are defined in the license:

1.5 "Extensions" means any Modifications, Derivative Works, or Required Components as those terms are defined in this License.

"Your extensions" are used in the following context:

1.14 "Serve" means to deliver Licensed Software and/or Your Extensions by means of a computer network to one or more computers for purposes of execution of Licensed Software and/or Your Extensions.

The word "your" is, in my non-lawyer opinion, added to emphasize the distinction between "licensed software" (the original software you obtained) and the "extensions" (your changes and additions).

Your program, as I understand it, would be considered a derivative work of the library.

A "user-visible display" means user interface that provides authorship/credits/copyright information. For example, at the bottom of this very page you might see:

site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. rev 2020.5.13.36813

In a GUI program the equivalent "user-visible display" could be the About dialog. In a console program the equivalent could be the output of foobar --version.

Whatever facility your program is employing, the requirement is that attribution to the authors of the library licensed under RPL is provided in that facility.

Note also that there is a requirement to provide attribution in documentation:

You must also include such User-Visible Attribution Notice in at least one location in the Software documentation where a user would be likely to look for such notice.

  • You are right that "Extensions" is defined in the license. I wasn't saying that it isn't. But "Your Extensions" isn't defined in the license. And the license text uses both terms - sometimes "Extensions", and sometimes "Your Extensions". Are you saying that they are the same? And why would then the legal text use two terms for one thing, without saying that they are meant to be the same, while it puts so much emphasis on definitions and actually putting the defined terms into double-quotes so that there is no ambiguity about what is being defined?
    – ZbynekZ
    Commented May 14, 2020 at 12:44
  • "Your extensions" are used to emphasize the distinction between your additions/modifications to the original program and the original program.
    – D. SM
    Commented May 14, 2020 at 20:53

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