>>22
But the book is less versatile.
An ebook has no weight. You can take it anywhere in a flash drive, so you can, for example, read it during lunch at work. If you want to read it on the way to work or don't want to read it off the screen, you can print a few pages and read it like that.
With a physical book, you have no choice but to carry the whole thing (if you don't want rip out pages). You can make copies of the pages, but that's also less convenient.
In any case, why is a programmer worried about reading off a screen? You're already staring at a screen for hours while working.