Academic code copied by library author The papers I write contain all the source code required to reproduce results. I have written a series of papers that build on each other over the years. My intention has been to release an open-source libary that encapsulates all of this, but I have not yet done so.

Before releasing anything I was contacted by the employee of a large company. They have been using my techniques and have decided to release an open-source version of their library. Their library contains code almost exclusively from my papers, copied verbatim. They clearly acknowledge my work in the documentation of their library.

My question is whether I ought to ask to be an author of the library. While I didn't commit code to the particular repository of that library, I did write the original code in papers. I'm worried that I'm not getting credit due for the work I've done if I'm not listed as a developer. I don't want to upset the authors of the library because a large ecosystem now depends on what they have done.
In fact something great happened: Your research did have impact in the real world and seems to be useful - not everyone can say that!

When it comes to legal issues, things are usually complicated and will involve copyright issues (of yours and of the journal / publisher) as well as authorship issues. Those vary between countries and it will be difficult to give an advise without proper juristical background and line by line comparison of your publications and the library code.

But as I understood your question, you are more interested in the academic credit, and therefore I would suggest to contact the authors, tell them you are happy that your work is used by them, and offer to be part of the development team. You might add a phrase like it would be a pleasure to be listed as author of the library - an in most cases they will understand...