uDMX

Probably the smallest USB-DMX Interface in the world!

Main Features

fits in your pocket
bus powered - no need for a wall-wart
can send DMX packets of arbitrary size from 1 to 512 channels. Only got 12 dimmers ? Don’t waste time sending 500 additional zeros 200 times a second…
command line tool
external for Max/MSP and PureData
open source