Libation - Audiobook Downloader and Converter

Amazon
recently announced its intention to prevent customers from being
able to download copies of their purchased audiobooks, a feature it had
supported since the inception of the Kindle. Amazon is also the company
behind Audible, the popular vendor of audiobooks. Although they have not
said they will be revoking download access to this service, it is a
possibility and audiobook owners looking for a way to back up what they
have purchased are looking for a solution to make this content useful
outside the Amazon walled garden.
The solution I am using is Libation, a FOSS title available on GitHub. Libation is a bare-bones application without a fancy UI, but it is fully functional and takes only a few minutes to set up and use. After it converted my audiobooks into M4B files, a standard audiobook format which allows bookmarks, I was able to play my books using VLC and various iOS apps like the free Audiobooks MP3 and M4B Player.
One warning - the file sizes are large. If you have a sizable collection, I would advise against downloading to your internal hard drive unless you have a lot of free space. Saving to an external drive would be a better option.
Features
- Import library from Audible, including cover art
- Download and convert all books to other audio formats (M4b and MP3)
- Download accompanying PDFs
- Add tags to books for better organization
- Powerful advanced search built on the Lucene search engine
- Customizable saved filters for common searches
- Open source
- Supports most regions: US, UK, Canada, Germany, France, Australia, Japan, India, and Spain
- Fully supported in Windows, Mac, and Linux