Audacity AU

Audacity is an FOSS audio editor. Audacity uses the AUP to store projects and up until version 2.4.2 used the AU audio format to store the project audio. Not to be confused with the Sun/NeXT AU files with the same extension.

File Information
AU block files are lossless/uncompressed PCM data. Metadata on their properties is in the AUP file. AU block files must be kept in the structure created by Audacity 2.x.