Back in 2007, a student (call him Student #1) approached me and asked a simple question: “Do I have to buy the book for this course, or can I get by without it?” The course was undergraduate operating systems (called “CS 537” at the University of Wisconsin—Madison). In teaching the course, I mostly relied upon notes developed by myself and my colleague Andrea Arpaci-Dusseau, and I still thought it was useful for students to have something to read outside of class. So I pushed back a little. “Yes, you should. It’s good for you to have another source for the material. Why don’t you want to buy it?” The student looked at me sheepishly and said, “Well, I, um, can’t really afford it.” The book we were using cost over $100, as do many textbooks today.
