.au extension

File Type Audio File
File Format Standard
Usage Open manually
Rank ★ ★ ☆  Average
Description

Audio file typically created on a Sun Microsystems or Unix-based machine; comprised of three parts: a header (containing 24 bytes), an annotation block (variable length), and the actual audio data.

Open With
Windows

Nullsoft Winamp

Microsoft Windows Media Player

Apple QuickTime Player

Macintosh

Apple QuickTime Player

RealNetworks RealPlayer

Adobe Audition

Updated May 10, 2012
Information from the PC File Extensions Reference
http://pc.net/extensions/file/au