The Arduino grblShield is a complete hardware solution for Dank’s CNC motion control system called grbl. The gbrlShield interprets a subset of rs274/ngc standard gcode and its streaming via console removes the need for a legacy parallel-port.  :)

More information on the grblShield can be found in the grblShield Wiki and the grblShield product page.  Don’t forget you can pickup your Uno and/or Mega from the Adafruit store.