.AUP File Extension

Audio project created with Audacity, a multi-platform audio recording and editing program; optimizes audio data by breaking larger audio files into several smaller pieces so Audacity can open and save projects quickly.

Audio files referenced by an Audacity project are saved in a directory with a similar name to the project file. I.e. the project "test1.aup," would store audio files in folder named "test1_data."