Reading ebooks

1 Calibre

Calibre isn’t a general metadata sync solution, but it does manage e-books well, especially ones that are real books and have ISBNs etc. And it does synchronize with various e-book readers and convert to their local dialect of whatever. (open source, although it is a giant bag of chaos and I defy anyone else to participate other than the creator.)

2 Thorium / Readium

Thorium Reader looks pretty good and seems to be developed by an open source consortium of library-inclined types.

• For a long time, there was no modern EPUB 3 compliant reading application usable on Windows, OSX and Linux, properly accessible for print disabled people, with a good support for the LCP DRM and capable of browsing OPDS catalogs.
• EDRLab decided to build such an application and release it for free, in order to provide users a great way to enjoy on a large screen EPUB publications, comics / manga / bandes dessinées, audiobooks, LCP protected PDF documents.
• Print disabled people now benefit from an EPUB 3 reading app which supports screen readers like Jaws and NVDA on Windows, Voice Over on Mac.

It is the flagship product of a complicated open source umbrella supporting the Readium project which I do not need to unsnarl here but important words here are

• EDRLab, the major developer
• Readium Architecture — in particular the Javascript-based Redadium 2 architecture ther is a Redium 1 which seems to be a different thing. See also GitHub - readium/architecture
• here is Readium 1 whcih is not easy to find from the EDR site
• readium/awesome-readium documents some other packages using their infrastructure.

3 Zotero

Zotero totally reads epub books since at least version 7.

4 Ubooquity

Ubooquity has been recommended to me also, have not tried it. Free for non-commercial use.

5 DJVu in particular

I’m not quite sure which app to use for macOS DJVU reading. Some candidates:

• DjVuLibre: Open Source DjVu library and viewer. Unclear if maintained. Maybe? The last file updates seem to be 2020 and seems not to be signed. However, it is offered as a package in homebrew as djview4.
• MacDjView, seems to have been updated in 2023, but not cryptographically signed.
• Cisdem Document Reader for Mac (USD20)
• DJVu Reader Pro (USD4)