0.5.0:
easyMP3Gain is a graphical user interface for mp3gain, aacgain and vorbisgain. The Interface looks similar to the one available for Windows.
It's a native GTK/GTK2 application, so it runs on Linux and FreeBSD/OpenBSD (not tested yet).
This version contains new features like:
 - Qt4 Version
 - Italian translation
 - Customizable columns (filename/path)

known bugs:
 - On some systems the application crahes when executing the OpenDialog. The problem depends on the theme "QtCurve". If this problem affects you, choose another theme such as Raleigh or Clearlooks.