I haven't heard anyone suggest Linux robots in this thread. Look at this thread<
http://www.chiefdelphi.com/forums/sh...ad.php?t=52563>. If you want to work towards Liunx/mac support you could write "dummy" code for the pic that would just forward the data from a Gumstix(or similar linux based device) to the I/O, and the thread above has already done this.
I think it would be better use of your time, and more adaptable to new technology to use a coprocessor. Not to mention the other advantages of a coprocessor.