MP3Gain written by Glen Sawyer
ReplayGain idea, concepts & website by David Robinson
Control buttons by Marc Heubeck
Help file by Bill MacEachern
The latest version of MP3Gain can be found at http://www.geocities.com/mp3gain/
For more information about ReplayGain analysis, please see the ReplayGain website at http://www.replaygain.org/
MP3Gain is completely freeware. No registration, no time limits, no disabled features, no annoying pop-up messages, or anything like that.
There will always only be one current version of MP3Gain, and that version will always be freely available to everyone.
With that said, if you really like this program and feel like making a donation to the author, you can find the appropriate information by clicking Help -> About in the menu.