🛡️ Warracker is an open source, self-hostable warranty tracker to monitor expirations, store receipts, files. You own the data, your rules!

BookLore: A self-hosted, multi-user digital library with smart shelves, auto metadata, Kobo & KOReader sync, BookDrop imports, OPDS support, and a built-in reader for EPUB, PDF, and comics.

Another alternative to Calibre/Calibre-web, perhaps?