Epubtools takes as input a series of chapters in a supported format and outputs a valid e-book in a supported format. At one time, this was only EPUB-2, but now other output drivers can be added. Note that if you run epubcheck on the result of an EPUB-2 output, you'll get the following two errors: ERROR: attribute "opf:role" not allowed here; expected attribute "dir" or "xml:lang" ERROR: attribute "opf:file-as" not allowed here; expected attribute "dir" or "xml:lang" This is not because it's an invalid EPUB-2 file. For an explanation of the issue, See: w3c/epubcheck#467 This package requires Python 3.x or above and the PyRTFDOM package (https://github.com/crankycyclops/pyrtfdom)