And the author doesn't even have to write the book for free. They could perfectly use a distribution platform focused on self-publishing (I mentioned GitBook a

And the author doesn't even have to write the book for free. They could perfectly use a distribution platform focused on self-publishing (I mentioned GitBook and Leanpub in a different comment). A good strategy would be to start writing the book and make it available in pre-order/beta for whatever amount ($20 maybe). It would probably take longer than 3 months to write since the author would have to work on the side, but so what? I'm not aware of a programming focused author who can actually cover their living expenses simply by writing.