Fission
Used by 3 peoplerogueamoeba.com ↗

“Oh, and I quite like Rogue Amoeba's audio software like Fission.”
Lee Martin Interview, Designer, developer · via Uses This 
“Fission for lossless sound editing (trimming live concerts into separate songs, etc.).”
Adrian Holovaty Interview, Web developer (EveryBlock, Django), musician · via Uses This