One of the features of Audion that set it apart from its rivals, particularly SoundJam, was its beautiful user-interface, which featured transparency through a process that mimicked the functionality of alpha channels.
Cabel Sasser has written that he and Steven Frank had one goal with Audion: "we wanted to listen to our music CDs on our computers while we worked, and we wanted it to be stylish."
Audion was originally conceived as one piece in a set of small applications to be called PanicPack, but time constraints led to the release of Audion 1.0 as standalone application on August 16, 1999.
Audion was known for its excellent MP3 decoder, which is reputed to produce sound with superior fidelity. Sasser said this was an accident, and that he and Frank have no idea how they achieved this.
Audion was retired on November 11, 2004.