In case someone makes a product based on my open source project, I'd like to have them to acknowledge my project with: "Powered by <MyProject>[link_on_Github]"

Is there a license similar to MIT, that forces to acknowledge the initiative works in a prominent place on a third party software?

  • I doubt this would be allowed by the Free Software Definition. Commented Jan 30, 2019 at 4:06
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    This is somewhat similar to the original BSD "obnoxious advertising clause" though that pertained to advertising material, not the program itself (but has the same lurking threat of explosive proliferation). I'd also have concerns about how prominent is "prominent enough" to satisfy this condition, and how to satisfy it in various UI contexts the program may use now and in the future (graphical, text, voice, used as a system library).
    – apsillers
    Commented Jan 30, 2019 at 4:58
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    Where do you want to require this attribution? For example, the Apache license has a clause about a NOTICES text file. And the GPL may require "Appropriate Legal Notices" to be displayed, but not necessarily the phrase "Powered by." In practice this information is displayed somewhere such as a manual, an "About" dialog box for a graphical tool, or via a --help command or similar for a command-line tool.
    – Brandin
    Commented Jan 30, 2019 at 6:30
  • @Brandin The contribution appearing in the "About" box or in the web site footer would work. The idea behind my question is that I want to be acknowledged visibly if my work is used as a fundamental to the other. Does it work like that?
    – Dmytro
    Commented Jan 30, 2019 at 12:26

1 Answer 1


Yes, a number of licenses explicitly allow reasonable attribution notices that must be preserved.

  • The Apache 2 license has the concept of a NOTICE file that must be made available to users, but not necessarily in a prominent place. It is sufficient to show them “wherever such third-party notices normally appear”.

  • The GPLv3 has a mechanism for Additional Terms which can be used to require the preservation of notices (section 7). However, the notices must be reasonable, which probably excludes a requirement to show them prominently.

  • The niche but OSI-approved Attribution Assurance License requires that some text is shown in the documentation, and in a prominent place upon launch of a program (e.g. a splash screen). However, the AAL is about ensuring attribution of original authors, not necessarily of a project.

It is easy to see how excessive attribution requirements could be abused to the point that such a software is no longer free. For example, there was a web application which required modified versions to show the original project's logo on every page. Such “badgeware” cannot be open source when it triggers attribution requirements on mere use of the software. Such requirements are only OK if they apply to derivative versions of the software.

Attribution requirements were actually a topic on the OSI's license-discuss mailing list in December 2018. You can read my summary here.

  • I see Attribution Assurance License fits my needs. But I don't understand how " attribution requirements on mere use of the software" make it non-free.
    – Dmytro
    Commented Jan 30, 2019 at 13:55
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    @Dmytro I would strongly encourage you to use the Apache license instead because it also assures attribution (though less visibly), but is much more commonly used. Regarding requirements on mere use: conditions that apply on distribution or modification are fine (e.g. “you must attribute the original version”). Conditions that must be satisfied by end users are not (e.g. “if you use my software, you must cite my paper” or “if your backend uses my database, you must put my logo on your website”).
    – amon
    Commented Jan 30, 2019 at 15:22
  • Do you think Attribution Assurance License may keep people or businesses away from using the work? My feeling pretty much clicks with what's been raised here opensource.stackexchange.com/questions/4221/…
    – Dmytro
    Commented Jan 30, 2019 at 18:32
  • I don't mind if someone sells my product as their own or whatever. Just want the end user be able to see easily, that my works has been used in the final product (or see me acknowledged as a contributor)
    – Dmytro
    Commented Jan 30, 2019 at 18:42
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    @Dmytro uncommon licenses definitively turn off contributors, but users might not care. There's no good way to prevent selling of binaries or rebranded versions of your application, but such shady practices only work with an information asymmetry. Having a decent project website that offers its own downloads should be enough to prevent that. The AAL doesn't help more than other licenses because it only applies to the software, not to a download page.
    – amon
    Commented Jan 30, 2019 at 19:24

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