Sometimes semplicity means really power. A simple and fast solution to create an EagleCad pcb to be milled by a milling machine can be realized directly with an eagle script. Download the gcode-1.ulp from Cadsoft, unzip and insert it as usual in ulp directory and run it after you have realized the board. Set the parameters according to your machine.
It generates a gcode list for a generic machine
To check the board run NCPlot (downloadable in the free software section). You can visually control the pcb to be milled.

Open the file with your preferred application (mach3, cncplayer, emc2, kcam4 ... ) and mill the board. That's it.