The Fourth Axis website http://www.fourth-axis.com/rotary-4t...axis-software/ offers postprocessors supporting rotary axis units on MDX-15 and MDX-20. Listed posts include ArtCAM and DeskProto and Modela Player 4.
They also have an emulator called FARM http://www.fourth-axis.com/farm/ that supports most all CAM software to drive the MDX-15 and MX-20 fitted with their rotaries. It works by emulating the JWX-10 and MX-40 + ZCL-40 which are both widely supported.
Unlike so many "rotary posts" that just index the rotary to an angle, the FARM emulator supports XZ-slicing, RotaryZ-slicing, Index Cutting (XYZ at any rotation angles) and Cylinder Wrap (mapping Y to A with suitable scaling).
A pleasant surprise to be able to use my Modela Player 4 (came free with the MDX) for every kind of rotary cut I could think of, on my little MDX-15.