I thought flowed text in PDFs was possible, but rarely used because it removes half of the benefit of PDFs (that is, page-exact references and rendering). Ther

I thought flowed text in PDFs was possible, but rarely used because it removes half of the benefit of PDFs (that is, page-exact references and rendering). There already is a solution, based on html and very easy to deal with: epub. Publishers are gradually shifting to it, even for things like science textbooks, as they realize that PDFs might look pretty but they're a usability nightmare. There are still some stupid things publishers do with epubs, but they'll get it right eventually; meanwhile the main text and font settings can be overridden by ereaders.