The project has versions for Windows, Linux and macOS, and even ARM builds for those using M Series macs and ARM on Linux.
Link here: https://github.com/rmcrackan/Libation
Surprised no one has mentioned OpenAudible. https://openaudible.org/
IMHO a paid and closed source program shouldn’t have “open” in their name
Is it just me, or does this pirate look like Network Chuck?
for Windows another good one is https://github.com/audiamus/BookLibConnect
Just to commenting to keep the knowledge: There are other projects that can de-drm audible. Amazon probably knows this and tolerates it. In fact, a long time ago all downloads on Linux did not have DRM. Those days are gone, but this https://github.com/mkb79/audible-cli should work.
As soon as you have ‘activation bytes’ many tools can play and convert the downloads.
Thank you for sharing 🙏