[Adoby]

Yes, but that doesn't mean that there isn't room for improvement. I agree that there currently is no real alternative to calibre. It is a killer app, in the sense that it would be very difficult to make a competing app from scratch.

However it would be very possible to make an open source app based on calibre that essentially is calibre lite. Aimed at the very big(?) group of users that find calibre difficult to understand and use.

For instance an app that doesn't have an internal library, but works like most mp3, movie and image media managers. Perhaps store paths to the books, not the books themselves, and update if files move. Use hashes to reconnect moved or renamed books to the database. It would be less efficient, more prone to file corruption and not very suitable for a large library. But I bet that a lot of people would love it.

It could be native to one operating system, and use conventions that are common in that operating system. That would make the app stick out less from other apps and perhaps lower the learning curve. The user base would of course be smaller. Or it could have a common codebase and functions with several different native user interfaces. More native than calibre is.

If it was built using the calibre codebase, then it obviously have to be open source and acknowledge the calibre origin. And also have its own support and so on, separate from calibre. But by building on calibre it could also be easier to develop. Things like conversion and book editing and metadata download, save to disk and device could perhaps be copied and used as is. Perhaps it would be possible to use automatic conversion from python to C or C++ to improve performance?

And of course calibre could benefit from users that grow out of "calibre lite" or even add design elements or other improvements.

Actually, I am surprised that there is no open source "calibre lite". That might even be a nice project for a group of students...