Ever struggled with a number of jack applications on your desktop everyone using its own master volume-fader but not one common place for all the volumes directly accessible?
The solution to your problem is JackMix, a mixer app for jack that looks exactly like the mixer you would use if you had to connect your analog equipment.
At least that is what it is supposed to be. For more info on the current and planned features visit JackMix:features. For more information about the concept and some internals of JackMix you should check JackMix:concept.
JackMix:links contains links to other jack-related apps and some audio-links.