On study-only licences

In my previous post, I mused on the value of Freedom Zero and of a non-free licence that allows for study but not for use:

I think it would have to be a licence that enabled studying, sharing and modification of the software, but that explicitly forbade any use for any purpose that isn’t studying, modifying or sharing. With a “contact me or my agent, tell us what you’re doing, and we’ll decide whether to grant you an additional licence for use” suffix. This is more open than closed proprietary software, but no more available for deployment to bad actors.

Waking up this morning I remembered that I have a copy of Numerical Recipes. This is a book, that contains code, and as such you can read the code. But not much else:

Without an additional license to use the contained software, this book is intended as a text and reference book, for reading and study purposes only. However, a restricted, limited free license for use of the software by the individual owner of a copy of this book who personally keyboards one or more routines into a single computer is granted under terms described on p.xix.

Page xix expands:

If you personally keyboard no more than 10 routines from this book into your computer, then we authorize you (and only you) to use those routines (and only those routines) on that single computer.

If you want to study, or to try things, knock yourself out. If you want to distribute things, or use things, get in touch and we’ll choose whether to sell you a licence.

This is not unexplored territory.