Wikipedia
Lucifox
Lucifox is a free and open source add-on for the browser Mozilla Firefox that organizes, saves and manages ebooks, supporting EPUB 3 and EPUB 2 formatted books without DRM and retrieval of books from on-line book catalogues using the Open Publication Distribution System (OPDS). It is part of the Lucidor suite of free and open source ebook software made by the Swedish developer Ordbrand.