Parallel Texts and eBooks

Menestrello has experimental support for bilingual EPUB 3 (Audio-)eBooks.

Try it yourself (or peek into the EPUB source):

(Please make sure you have enabled the options Open EPUB 3 notes in footer and Open translations in footer in the app Settings.)

Currently, this works thanks to a naming convention, but nothing (at least, from the technical point of view) impedes to define a custom namespace and related attributes, and insert them into the XHTML code. (Q: is there anything like that out there?) The same goes for the app, which might offer more displaying options, support for multilingual (not just bilingual) eBooks, and an even more refined UX. Please read this discussion for further details on this issue.