I've seen I guess what are called "smoothsteppers" for Mach3, which take input from (I think) USB or Ethernet and convert that to a parallel output that can be used to drive a card like a Xylotex.

I was wondering, are there any CNC stepper controllers that have this feature built-in, that are halfway decent (do a good job driving steppers and have some resonance reduction built in, etc.)?