How To Add MP3 Support to Audacity (to Save in MP3 Format)
Audacity tutorial: Converting to mp3 or AAC and other formats, example: Matthew Smith - epic orchestral synth music for film and game effects; Buanzo's LAME mp3 library
Portable Audacity 3.1.3 Free Download for Windows
Installing and updating Audacity on Linux - Audacity Manual
Audacity can't find LAME library, I can't save Mp3? - Ask Dave Taylor