The Stribe is a really cool
open source music controller. It takes some serious soldering skills to make one, but the end results are fantastic. Check it out at Maker Faire in Austin.
Eight touch-sensitive strips are flanked by dual columns of LEDs, providing subtle fingertip control coupled with illuminated feedback. The Stribe’s firmware communicates via USB with music programs such as Max/MSP and Reaktor.
More about The Stribe
[Editor's note: Not actually open source it seems, non-commercial license - pt]