Downloads

AACGain support: You will also need to download AACGain, rename it to "mp3gain.exe", and put it in the MP3Gain folder after installation.

Here's a list of what you'll find at the SourceForge download page for MP3Gain.
There are two Mac ports that I know of: MacMP3Gain, and MP3Gain Express.

MP3Gain-Windows (Stable)
mp3gain-win-1_2_5.exe Normal MP3Gain install for version 1.2.5
This is what most people will want to download.
mp3gain-win-1_2_5.zip Normal MP3Gain, but with no installer
mp3gain-win-full-1_2_5.exe Exactly the same as the Normal install, but also includes the Microsoft Visual Basic run-time files. The VB run-time files only need to be installed on a computer once, so they might already be in your Windows folder. If you're not sure, then go ahead and download this Full version. Or if you want to save some download time, then try the Normal install first.

If you ever download a newer version of MP3Gain after doing a Full install, you will only need the Normal version.

mp3gain-win-full-1_2_5.zip Full MP3Gain (i.e. Normal MP3Gain plus VB run-time files), but with no installer
mp3gain-win-gui-1_2_5-src.zip Visual Basic source files used to create the MP3Gain GUI. The GUI is just a front end for the command-line program mp3gain.exe, so if you want to completely re-compile MP3Gain from scratch, then you'll also need the mp3gain-1_5_2_r2-src.zip file.
MP3Gain-Windows (Beta)
mp3gain-win-1_3_4.exe Normal MP3Gain install for version 1.3.4 Do not use this version unless you really need the experimental Unicode support. There seem to be some cases where this version accidentally shortens the filename. I'm still figuring it out.
mp3gain-win-1_3_4.zip Normal MP3Gain, but with no installer
mp3gain-win-full-1_3_4.exe Exactly the same as the Normal install, but also includes the Microsoft Visual Basic run-time files. The VB run-time files only need to be installed on a computer once, so they might already be in your Windows folder. If you're not sure, then go ahead and download this Full version. Or if you want to save some download time, then try the Normal install first.

If you ever download a newer version of MP3Gain after doing a Full install, you will only need the Normal version.

mp3gain-win-full-1_3_4.zip Full MP3Gain (i.e. Normal MP3Gain plus VB run-time files), but with no installer
mp3gain-win-gui-1_3_4-src.zip Visual Basic source files used to create the MP3Gain GUI. The GUI is just a front end for the command-line program mp3gain.exe, so if you want to completely re-compile MP3Gain from scratch, then you'll also need the mp3gain-1_5_2_r2-src.zip file.
mp3gain (command-line back end)
mp3gain-1_5_2_r2-src.zip C++ files (plus Visual C++ project information files) used to create the mp3gain.exe back end
mp3gain-dos-1_5_2.zip Command-line only version of mp3gain. If you download any of the Windows MP3Gain files above, this file is included.

Get MP3Gain at SourceForge.net. Fast, secure and Free Open Source software downloads