[linux-audio-user] Anyone know of a Volume Leveler?

[Steven P. Ulrick]

Hello, Everyone :)
Does anyone know of a good volume leveler that I can use on Red Hat 9? 
To clarify what I mean (if you didn't figure it out already), I want
something I can run wav or mp3 files through and make them about the
same volume, so that when I make CD's from varied sources, I don't have
any jarring, unpleasant transitions between songs.  I would prefer a
command line utility, but I will be willing to try a graphical program
if necessary :)
I already searched for this item on Google, and on freshmeat as well :)

Thanks in advance for your help :)
Steven P. Ulrick