Sounds like an obituary, but I'm running a Mac PowerBook with OS X 4.11, and somehow I'm able to keep a functional Audion 3.02 on the dock. I keep it primarily for editing MP3 files rather than as a player. Its waveform editing is simple to use if I want to whack out a quick extract from of a full tune.
Still sounds great, and gives me a vast array of MP3 encoding options/bit rates. Has it stopped being usable on other platforms?