GSF is an emulated Game Boy Advance audio format based off of Neill Corlett's PSF (Portable Sound Format), developed by CaitSith2 and Zoopd. GSF files appear as either .minigsf or .gsf, mostly being of the former. The .gsflib must be extracted into the same directory as the .minigsf files. Currently, Nullsoft's Winamp and the Highly Advanced plugin for Winamp are required to play these emulated audio files.