LameXP - LameXP is an Audio Encoder Front-End, a graphical user-interface for a number of audio encoders.
MP3Gain - A free automatic mp3 volume normalizer.
FLAC - A free, open source codec for lossless audio compression and decompression
easyMP3Gain - Graphical User Interface (GUI) for MP3Gain, VorbisGain and AACGain (enables you to modify the...
WavPack - WavPack is a completely open audio compression format providing lossless, high-quality lossy, and a...
wxMP3gain - Needs to be compiled.