calibre

calibre is an e-book manager that handles a whole library from one desktop app. It views, converts, edits, and catalogs e-books across all the major formats, and runs on Linux, Windows, and macOS.

It can also talk to e-book reader devices to move books on and off them. It fetches metadata for your books from the internet, and it can download newspapers and convert them into e-books for convenient reading.

calibre is built around a local library on your own machine rather than a hosted account. It is the work of volunteers from all over the world, with binary builds and installers for every supported platform and a source tarball for the current release.