How to properly credit the authors of a package that you extend

[Moody_Mudskipper]

I've been working on a new package that extends magrittr, it's based on a fork though not much of the original code remains. It mainly consists of:

• a couple functions from magrittr that I copied and modified
• a fair amount of calls to foo <- getFromNamespace("foo ","magrittr") to be able to use modified functions with the unexported functions of magrittr
• my own code

I don't think it's standard practice to add as authors people that didn't directly participate, as it might appear to imply that they endorse the project while they might not. Here it's really mostly a wrapper though, so I don't know what I should do.

[JohnMount]

I'd say perhaps the polite thing to do is to ask the package authors and copyright holders what they would like. I have seen both directions, but you are correct it is hard to guess what others may want.

However, magrittr DESCRIPTION claims it is under an MIT license (the the LICENSE file lists copyright and doesn't have the text of a license). If it is indeed under an MIT license these licenses tend to be described as follows (from Wikipedia):

Copyright (c)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

It may in be easy for an MIT licensed derived work to satisfy the few described obligations.

[Moody_Mudskipper]

Thank you John, I ended up sending an email to Stefan as you suggested, I suppose it's one of those things that have no strict rule.

I remember reading someone suggest to Hadley that he integrates in ggplot2 some work that had been done in other packages and he answered in the line of "I don't want to steal people's work", while this work was free. And I assume he might feel ripped off in the reverse situation id he says that. So obviously, it's not just a matter of legal license, there is still a sense of property of ideas even if you give away your rights on your ideas.

[JohnMount]

Sounds good. I knew I couldn't really give a definitive answer. But I wanted to try and get the thread going, as it is a good question.

[Moody_Mudskipper]

For what it's worth for this specific case Hadley asked to set him and Stefan as Authors with role = "cph" (copyright holder) .

[JohnMount]

If you decide to do that I would suggest making sure there is also "cph" for yourself (so it doesn't look like you have no rights), and also annotating the "cph"s as to why they are there (as shiny does https://github.com/rstudio/shiny/blob/master/DESCRIPTION ). Just some text in the comment such as "for magrittr portions" might help make intent clear.

[Moody_Mudskipper]

Great advice John thanks a lot!