iVolume for Mac

From Manfred Schwind:

Tired of constantly adjusting your music's volume?
iVolume ensures that all your songs play at the same volume level.

iVolume calculates the volume perceived by the human ear for each song of your iTunes music collection. Thereby iVolume gets the most out of the approved Replay Gain algorithm and adjusts your songs according.

Compatible With Your Digital Life
iVolume integrates seamlessly with iTunes on Mac and PC, iPod, iPhone, Apple TV, FrontRow and AirTunes. Most popular audio file formats like MP3, AAC, AIFF and Apple Lossless are supported.

Blazingly Fast
iVolume takes advantage of newest technologies to fully utilize every core of modern multiprocessor machines for optimal performance.

Avoids Unnecessary Work
iVolume remembers all results ever calculated. Apply changed adjustment settings without the need for re-analyzing your songs.

Keeps Albums Intact
By using a sophisticated album detection algorithm iVolume optionally adjusts albums as a whole to keep the intention of the artist. This method is particularly suitable for adjusting gapless live albums.

Highly Configurable
Create groups to apply individual fine tuned settings to any specified subset of your songs.

Awesome Usability
All the features above are fun and incredibly easy to use through a modern and clear user interface.