Sound Forge 8.0, originally released by Sony Creative Software (and later acquired by MAGIX), was a professional 2-track audio editor. It offered a comprehensive suite of tools for audio editing, mastering, and design.
If the MP3 Plug-In 2.0 specifically refuses to activate (as it often required a separate, paid license to Fraunhofer), many long-time users recommend these workarounds: soundforge+80+sony+mp3+plug+in+20+activation+code+exclusive