I'm working my way through my machine controller system. 1 DSP, 4 motor boards, plus network for additional expansion.
I'm basing the design on some of the working theories of the motion controllers I've seen at work. I'm starting with PID synchronizing servos and some of the IO as a background priority PLC. Beyond this is the interfaces I'm hoping for.
Beyond my own programming interface, I want three different control interfaces. One, connect to the RepRap software package for doing FDM (maybe the Fab@Home software too). Two, G code for a lot of generic CNC and motion work. Three, an HPGL printer driver for doing generic 2D and 2.5D work. This would allow for very simple control of any 2D table style pen plotter printing system. With the right hardware, a router, laser, or anything else would be possible.