I came across this while browsing Kickstarter. It looks like an interesting project.
Specs:
Fully Open Source Hardware and Well-Commented C Software Design
Digital Analog Hybrid Circuitry
2 Digital Oscillators with 16 waveshapes, updateable to more
2 Low Frequency Modulation Oscillators with 10 destinations
Innovative Digitally-Controlled Analog Filter with Low-Pass, Band-Pass, and High-Pass with Envelope Control and External Audio Input
Analog Voltage-Controlled Amplifier with Envelope Control
Drone/Loop Mode for Playing by Itself
19 Knobs to Twiddle and 8 Switches
Full MIDI Input and Output
Sound Patch Save and Recall
For $25 pledge, you get the board, the microprocessor and the list of other needed parts. The video demonstrates some interesting sounds. Very lo-fi.