I loved using hyperMidi back in the day with HyperCard:
http://www.earlevel.com/

I wish we could get Nigel Redmon, the writer of the HyperMidi external to update it to work with RunRev. Being able to access data coming into and going out of a Midi to USB interface would open up tremendous possibilities for musicians. Wonderful things like custom Midi utilities, synth editors, and synth librarians could be written in RunRev.