Free RMS normalize program?

[Cooker]

I'm looking for a freeware for a friend that can normalize audio to a certain RMS value.

Its for mastering evaluation so one can compare the mix to master without the loudness difference, simultaneous playback/instant soloing of the 2 tracks would be nice too.

[The Noodlist]

There's something like you mention for Rea js. Spectrum matcher, or something.
Spectrum Matcher
MLoudnessAnalyzer
AB Level Matching Tutorial Using Free Plug-ins
Auto Gain Staging JSFX

[Cooker]

edit; deleted.