MP3Gain analyzes and losslessly adjusts mp3 files to a specified target volume.
It does not simply do peak amplitude normalization. Instead, it performs statistical analysis to determine how loud the file actually sounds to the human ear.
AMaMP (Audio Mixing & Manipulation Project) aims to provide a cross platform core program that, based on an input instruction file, mixes and manipulates audio from a range of sources. The project incorporates GUI apps that target the core.