Why are Numerical Recipes and Cambridge University Press now requiring the plugin?
A1. We are building a unified infrastructure that allows us to deliver all of the following: (i) free content that is in the public domain; (ii) content that is copyrighted, but nevertheless free; and (iii) copyrighted content by subscription. To do this in today’s world we must satisfy authors and publishers that their interests are not being completely disregarded. Of course, we must also satisfy users that the infrastructure is workable and efficient.
