Rui's note on qjackctl prompted me to look at http://www.rncbc.org and then http://www.rncbc.org/drupal/node/191 which lead to
http://qmidictl.sourceforge.net/ and http://qmidinet.sourceforge.net/ ... 

Both of these apps look awesome. Any chance these can be made available through PlanetCCRMA or even better, through fedora which already carries up-to-date versions of qtractor.

Also, one issue I've found w/ controllers in general is that there is a need for a simple scripting language, or a comprehensive set of "built-in special functions" to handle "state" and "computation" in midi controllers. Do qmidictl or qmidinet have any solutions for this?

One quick example I ran into recently. I've setup a very useful remote control to a TC Electronics Finalizer. One of the features it has is a MIDI-controlled "fader" (e.g. for doing smooth fadeouts/fadeins). I've got that mapped to a 100MM slider on a behringer controller and it's SWEET. But also, it's linear. What I need is to map the midi controllers 0-127 to a logarithmic curve so as to match human loudness perception. This doesn't seem possible in qmidiroute... (?) What tools would allow this, or any other "computed" mapping to be done? (see also see http://old.nabble.com/using-qmidiroute-for-midi-device-control....-ts27963116.html ) 

Is there an easy way to add scripting languages to Qt apps? (something like 'Guile' would be nice).

Niels
http://nielsmayer.com

PS: thanks to http://www.rncbc.org/drupal/node/183 , I will also be taking a look at qtractor-0.4.5-1.fc12.x86_64 which i've installed, but not yet explored ( rosegarden4-10.02.1-1.fc12.x86_64 works well for me so far).