Updated 30-Jan-2022
Tools change over time, but it seems that in the Epub world we have more of the same. As of November 2018: - Calibre's Epub Editor is pretty nifty - Sigil development stalled, then picked up again - Pagina Epub Checker is still under development and useful - Pandoc with or without some kind of TeX, LaTeX, or XeLaTeX -- the last one is better for font support Things haven't really changed over the past X years, much. Certainly not since the 2017 note on Epub tools.