Mach itself does work past XP, however it's the parallel port driver that suffers under later versions of windows. The driver can be made to run under Vista, but can be a bit hit or miss.

As Robin has said, if you go USB, you are at the mercy of that vendor, however go for something proven and popular, then you shouldn't have any issues. KMotion and SmoothStepper are the common options that can still utilise Mach3 (KMotion can work standalone), but there are a couple others that don't rely on Mach.


I've been following Art's and Brian's posts on the Mach Yahoo group over the past month, about the development of Mach 4 and a new Parallel Driver, along with the issues they're facing, and basically short of some major coding, the parallel port driver isn't going to work with any new versions of windows.
On the plus side, Mach4 is basically going to be a quite minimalist core, with planning, motion and interfacing all dealt with by plug-ins, so is going to open alot of new possibilities.