Free variables, open access

Sat 31 Mar 2007 01:06 PM

I just uploaded forall x version 1.22, which includes several small changes in response to helpful, unsolicited feedback from Craig Erb. The bigger change with this version is that the license now allows commericial use.

It has been about a year and a half since I released the first version. As I have said before, the goal was to provide instructors with an alternative to commercial textbooks. As such, I opted for a license that prohibited commercial use. Since then, 1000s of people have downloaded the book and it has been used at several universities.*

I have since come to realize that the noncommercial restriction might discourage legitimate uses of the book; other sites offer extended discussions of this point. The most recent version uses the Creative Commons Attribution-Sharealike license. Users are still required to acknowledge me as author of material in the book, and any derivative works must be offered under an open license. However, they may use the work or derivatives for commercial purposes. As a result of the fine print, derivative works may more readily include materials published under other open licenses.

There is little danger that a publisher will sell an overpriced deluxe edition of forall x, because the Sharealike provision would preclude them from exercising restrictive rights over it. The content would still be free.

And now it's more free than ever.

* The numbers are hard to pin down. The PDF on the main site is downloaded over 30 times a day, but lord only knows how many of those are by actual readers. I get occasional e-mails from people who have read and enjoyed parts of the book, I have corresponded with several people who have used it as a course text, and web traffic suggests that the text has been recommended at some other schools. People are under no obligation to tell me when they assign or use the book, however, and typically they do not.