New GUI at http://www.geocities.com/mp3gain

Only one difference between 0.7.5 Beta and 0.7.4 Beta:
The "Group" maximize feature has been re-named and now works with the "Each folder is an Album" option.

In other words, if you have a whole bunch of mp3s in the list and you click the menu item "Apply Max No-clip Gain for Album", mp3gain will look at all the mp3s in each "album" (folder), find out how much they can all be amplified without any of them clipping, and then applies that single gain change to each of the files in the album.