Virtual MIDI keyboard for JACK MIDI

 JACK keyboard is a program that allows you to send JACK MIDI
 events (play ;-) using your PC keyboard. It's somewhat similar to
 vkeybd, except it uses JACK MIDI instead of ALSA, and the default
 keyboard mapping is much better - it uses the same layout as
 trackers (like Impulse Tracker) did, so you have two and half
 octaves under your fingers.