Alexandria is a program for organising collections of books. It

* retrieves and displays book information (including cover pictures) from
several online libraries, such as Amazon, Proxis and Barnes and Noble
* allows books to be added and updated by hand
* enables searches either by EAN/ISBN, title, authors or keyword
* can import and export data into ONIX, Tellico and ISBN-list formats
* features a HIG-compliant user interface
* handles book rating and notes
* supports CueCat (R) barcode readers

Website: http://alexandria.rubyforge.org/