If it’s multilang it’s better.
Thx in advice.
Unironically the library. Then just use something like Audiobookshelf to organize your collection.
The library in my town is nothing fancy like the ones from the USA (just old old educational books and I got caught on some books of the first PC viruses lol), but hey, at least they had this gem.
I don’t think that Libby itself is. There’s DRM and while there is probably a way to strip it, I don’t think that is easy and/or publicly shared. But Overdrive, which is Libby’s predecessor, allows for DRM free MP3 downloads. But they’ve been trying to sunset Overdrive for a long time. The Windows desktop program needed to download the MP3 files is no longer linked on their site, for example (but is still downloadable if you know the exact link). I’m honestly not sure why it even still works unless it’s to comply with some ancient contract they have with a library somewhere.