Mickey Petersen has a really interesting post on the technical details of how he wrote Mastering Emacs. It’s not surprising that he used Emacs, of course, but less obviously he chose reStructedText as his source format. That choice was driven by the fact that he wanted to produce both PDF and ePub output. My first thought was, “Why not use Org?” but Mickey says that Org documents have problems being converted to other formats. I export Org to HTML and LaTeX all the time with no problems at all but I don’t know how the ePub would play. Even Knuth won’t recommend an ePub version of The Art of Computer Programming because he can’t make the output faithful to his intentions.
Many publishers these days require that a book manuscript be delivered in docx format. My thoughts on Word are well known. I would never undertake to write a book—or anything, really—in Word (or any of its unholy siblings) but it does provide one very useful feature: the ability for copy/technical editors to suggest changes in the manuscript, which the author can accept or reject on a per suggestion basis. Mickey shows how to do the same thing with ediff.
As with all of Mickey’s writings, you’re sure to learn a couple of things you didn’t know from his post so it’s worth reading even if you have no interest in writing a book. If you are interested in producing a book, it’s essential reading.