Publisher:Brilliance Audio
Founded by R. Michael Snodgrass in 1984. Produced audiobooks on cassette at first, but nowadays tends to produce CDs and MP3 CDs and downloadable audio e-books.
It's perfectly possible that we'll need to record Library editions and Normal editions of cassette, CD, and MP3 CD versions of a title, instantly outnumbering the physical paper editions produced. Especially as they often produce Unabridged versions as well as cheaper Abridged versions.
They also had a "Bookcassette®" format where the left and right stereo channels were used to record different tracks - twice as much content on each side of the tape. As this requires a cassette-player with complete balance control, it's worth highlighting those as different from other audio-cassette formats, e.g. here. Fortunately for us they don't use that anymore.