Originally Posted by Guilgamm
What with all the e-book sharing going around, and everybody using Calibre, personal libraries have become an appaling mess, and duplicates, triplicates, a curse.
I think you may be missing the point. Calibre's library is what you see when you're using the program.
If the program chose to store its data in a single database you wouldn't be making this complaint, as multiple copies in different formats, or authors named slightly differently in the underlying paths wouldn't be visible. The fact that it stores its data in a readable file structure doesn't make that the library.