I’m a big fan of littleBits modules, so it’s great to hear that these are being made available.
MIDI module Allows you to control the Synth Kit from a DAW (Ableton Live, Pro Tools, etc) and other MIDI-enabled instruments. Additionally, it will allow you to create your own MIDI controller with littleBits modules by converting littleBits control voltages to MIDI messages.
CV module Allows you to Integrate your Synth Kit with other analog synthesizers (for example, modular synths or analog keyboards).
USB I/O module This is a USB audio interface that will enable you to record directly into your DAW from the Synth Kit or send audio from your DAW to the Synth Kit for processing. Integrate your Synth Kit with common audio work stations (Ableton, ProTools, or other software like Traktor or Max/MSP).