Even better suggestion, If you've used Markdown or similar to write the book, relese the source (and an artifact, i.e. EPUB). I have seen so many books that I w

Even better suggestion, If you've used Markdown or similar to write the book, relese the source (and an artifact, i.e. EPUB). I have seen so many books that I wanted to read but couldn't, because EPUB and PDF aren't great when it comes to accessibility, particularly with maths and diagrams. Getting access to the Markdown source usually solved all of my problems.