It was originally a commercial (shareware) program, but with the dominance of Apple's iTunes, development was halted and it was released as freeware.
[1] One of the features of Audion that set it apart from its rivals, particularly SoundJam, was its user interface, which featured transparency through a process that mimicked the functionality of alpha channels on Mac OS 9's QuickDraw, a graphics system that did not support them.
[2] Apple tried to meet with Cabel and Steven to hire them to create the original version of iTunes based on their work on Audion.
The meeting never took place, and Apple instead acquired Audion rival SoundJam MP as the basis for iTunes.
In March 2020, Panic announced they would be updating hundreds of Audion's unique "faces," or skins, to work with modern versions of macOS.