Datalogics has a reader for PC (DL Reader:
http://www.datalogics.com/products/rmsdk/dlreader.asp). I have download links for Nook books (text link under the buttons for each book) and the DL Reader acts just like Adobe Digiital Editions, but the books end up in "DL Library". If you don't complete the hashtag business in DL reader, the books "land" initially in downloads, and can be imported into calibre. Alf magic works just fine on these books either way.