Mixer.app is a mixer utility for Linux/FreeBSD systems. It is designed to be docked in Window Maker. This utility has three volume controllers that can be configured to handle any sound source, the default sources are master-, cd- and pcm-volume. Sound sources can easily be muted and there is also wheel mouse support.
For comments, see the original dockapps.org entry.
This dockapp is not maintained by the Window Maker Developers Team. Please visit the dockapp's website for downloads.