> I cannot imagine doing all of that myself and making the app free at that.
The only reason we are here talking about it is because its free software. Its not even about price, its about how Calibre evolved thanks to a community that grew around it. Maybe someone could start a proprietary ebook library program, charge for it, and make a living that way. But it would get orders of magnitude less usage and have done that much less good for the whole of mankind as a result. And the work of one person, or even a small team, is unlikely to accomplish all the features Calibre has because few people will recognize the collective needs of all book readers the way an open bug tracker and merge requests can.
The only reason we are here talking about it is because its free software. Its not even about price, its about how Calibre evolved thanks to a community that grew around it. Maybe someone could start a proprietary ebook library program, charge for it, and make a living that way. But it would get orders of magnitude less usage and have done that much less good for the whole of mankind as a result. And the work of one person, or even a small team, is unlikely to accomplish all the features Calibre has because few people will recognize the collective needs of all book readers the way an open bug tracker and merge requests can.