https://calibre-ebook.com/download_linux

calibre is an e-book library manager. It can view, convert and catalog e-books in most of the major e-book formats. It can also talk to many e-book reader devices. It can go out to the Internet and fetch metadata for your books. It can download newspapers and convert them into e-books for convenient reading. It is cross platform, running on Linux, Windows and macOS.

Use Calibre to Remove DRM from Kindle Books and Convert to PDF
https://itsfoss.com/calibre-remove-drm-kindle/

Frequently Asked Questions
https://manual.calibre-ebook.com/faq.html

The calibre Content server
https://manual.calibre-ebook.com/#the-calibre-content-server

7 Hidden Calibre Features That'll Help You Manage Your Ebooks Better
https://www.makeuseof.com/tag/hidden-calibre-features-manage-ebooks/

Les livres ePub audio arrivent dans Calibre 7
https://goodtech.info/calibre-7-nouveautes/
https://www.readbeyond.it/ebooks.html